SNA+MC 2010 Summary Paper - plasma2012.iyte.edu.tr/docs/abstract book-PLASMA2012.pdf · Oscillations in High-Tc Superconductors (PLASMA 2012)” being held

1

PLASMA 2012

The 8th International Symposium

on Intrinsic Josephson Effects

and Plasma Oscillations in High-Tc

Superconductors

June 10 - 13, 2012

Radisson Blu Resort & Spa,

Cesme, Izmir, Turkey

http://plasma2012.iyte.edu.tr

The 8th International Symposium on Intrinsic Josephson Effects and Plasma Oscillations in High-Tc Superconductors (PLASMA 2012)

Izmir Institute of Technology, Izmir, Turkey, June 10-13, 2012

2



3

Preface

On behalf of the Conference Committee, I would like to warmly welcome to everyone

participating to the “8th International Symposium on Intrinsic Josephson Effects and Plasma

Oscillations in High-Tc Superconductors (PLASMA 2012)” being held in Çeşme, Izmir,

Turkey, from June 10 to 13, 2012.

This series of symposium was initiated by T. Yamashita (NIMS, Japan) and M. Tachiki

(Univ. of Tsukuba, Japan) on the occasion of the novel Josephson plasma phenomenon in

high temperature layered superconductors. This symposium is the 8th one followed by

Hirosaki (2010), Pohang (2008), London (2006), Tsukuba (2004), Pommersfelden (2002),

and Sendai (2000, 1997). The conference will bring prominent scientists together from

various countries, with a common objective to share their new ideas, and research findings

and experience and promote stimulus discussions. PLASMA 2012 is being the most

comprehensive and scientifically popular conference in the hot topics related to strong,

coherent and continuous terahertz radiation phenomena, including much of the advances in

the field of terahertz science and applications and noble macroscopic quantum phenomena

and others. No doubt, it provides an excellent opportunity for the participants to involve

themselves in extremely fruitful interpersonal exchange of ideas, perspectives and outlooks.

Additionally, Izmir hosts a large number of extremely important architectural and

cultural sites. The town is nicknamed as the Pearl of the Aegean and Cesme in İzmir is

surrounded by the Aegean Sea in three sides at the very western end of Urla Peninsula and is

neighbor of the Sakiz (Chios) Island. My wish is that you will all join us for a symphony of

outstanding science, and take a little extra time to enjoy the unique beauty of Çeşme and its

surroundings.

Finally, we want to express our special gratitude to all the participants, and we would

also like to thank our colleagues in the Conference Committee, whose commitment enabled

us to achieve our goal. In the spirit and tradition of Turkish hospitality, we once more

welcome you all to PLASMA 2012, I would like to wish you a nice and enjoyable stay in the

Çeşme, may you all return home feeling recharged and ready to continue the invaluable

explorations.

Best regards,

Lutfi Ozyuzer

Chair



4

Conference Scope

The PLASMA 2012 conference covers the whole aspects of the intrinsic Josephson junctions

and the related Josephson effects from fundamentals to applications.

More specifically,

1) Terahertz oscillations and their applications

2) Macroscopic quantum phenomena and qubit applications

3) Josephson vortex dynamics and related topics

4) Josephson plasma (collective excitation) and related topics

5) Josephson effects in intrinsic Josephson junctions and related systems

6) Others (including iron-based superconductors)

7) Exotic and unconventional superconductors and their properties



5

International Organizing Committee

International Scientific Committee

Lutfi Ozyuzer (Turkey) [Chair]

Kazuo Kadowaki (Japan) [Co-chair]

Alexey V. Ustinov (Germany)

August Yurgens (Sweden)

Ekrem Yanmaz (Turkey)

Jian Chen (China)

Ken E. Gray (USA)

Kemal Kocabas (Turkey)

Lev Bulaevskii (USA)

Nejat Bulut (Turkey)

Peiheng Wu (China)

Sang-Jae Kim (Korea)

Takeshi Hatano (Japan)

Tsutomu Yamashita (Japan)

Yıldırhan Oner (Turkey)

Local Organizing Committee

Lutfi Ozyuzer (Izmir Inst. Technology)

Nejat Bulut (Izmir Inst. Technology)

Yasemin Demirhan (Izmir Inst. Technology)

Fulya Turkoglu (Izmir Inst. Technology)

Hasan Koseoglu (Izmir Inst. Technology)

Hakan Alaboz (Izmir Inst. Technology)

Hilal Saglam (Izmir Inst. Technology)

Mutlu Yaman (Izmir Inst. Technology)

Şebnem Yazici (Izmir Inst. Technology)

Adnan Taşdemir (Izmir Inst. Technology)

Halil Arslan (Izmir Inst. Technology)

Koray Sevim (Izmir Inst. Technology)

Göktan Tosun (Espresso Congress & Tourism)



6

List of Participants

Invited Speakers

Alex E. Koshelev Argonne National Laboratory, Illinois, USA

Alexander M. Klushin Institute for Physics of Microstructures RAS, Russia

Fedor V. Kusmartsev Loughborough University, UK,

Hidehiro Asai University of Tsukuba, Japan

Hideki Matsumoto Tohoku University, Japan

Huabing Wang National Institute for Materials Science, Tsukuba, Japan

Hu-Jong Lee Pohang University of Science and Technology, Korea

Itsuhiro Kakeya Kyoto University, Japan

John F. Zasadzinski Illinois Institute of Technology, USA

Kazuo Kadowaki University of Tsukuba, Japan

Kazushige Machida Okayama University, Japan

Kensuke Nakajima Yamagata University, Japan

Masahiko Machida Japan Atomic Energy Agency, Japan

Mehdi Fardmanesh Sharif University of Technology, Iran

Niels F. Pedersen Technical University of Denmark, Denmark

Paul A. Warburton University College London, UK

Paul Müller Universität Erlangen-Nürnberg, Germany

Reinhold Kleiner University of Tübingen, Germany

Richard A. Klemm University of Central Florida, USA

Shi-Zeng Lin Los Alamos National Laboratory, USA

Takanari Kashiwagi University of Tsukuba, Japan

Tim M. Benseman Argonne National Laboratory, Illinois, USA

Tomio Koyama Tohoku University , Japan

Tsutomu Yamashita Tohoku University, Japan

Vladimir Krasnov Stockholm University, Sweden.

Xiao Hu National Institute for Materials Science, Tsukuba, Japan

Yong-Joo Doh Korea University Sejong Campus, Korea

Yoshihiko Takano National Institute for Materials Science, Tsukuba, Japan

Yuri I. Latyshev Kotelnikov Institute of Radio-Engineering and Electronics, Russia

Yury Shukrinov Joint Institute for Nuclear Research, Russia

Ziya Saglam Aksaray University, Aksaray, Turkey



7

Contributed Talks

Posters

Alireza Kokabi Sharif University of Technology, Tehran, Iran

Ayten Cantas Izmir Institute of Technology, Izmir, Turkey

Boris Gross University of Tübingen, Germany

Burcu Cevizci Dokuz Eylül University, Izmir, Turkey

Feng Liu National Institute for Materials Science, Tsukuba, Japan

Fulya Turkoglu Izmir Institute of Technology, Izmir, Turkey

Hakan Alaboz Izmir Institute of Technology, Izmir, Turkey

Hasan Koseoglu Izmir Institute of Technology, Izmir, Turkey

Hazem Abdelhafiz Nile University, Egypt

Hilal Saglam Izmir Institute of Technology, Izmir, Turkey

Ilhom Rahmonov Joint Institute for Nuclear Research, Dubna , Russia

Jamal Akhtar Khan Salman bin Abdulaziz University, Saudi Arabia

Kaveh Delfanazari University of Tsukuba, Japan

Mesude Saglam Ankara University, Turkey

Minoru Suzuki Kyoto University, Japan

Akinobu Irie Utsunomiya University, Japan

Jie Yuan National Institute for Materials Science, Tsukuba, Japan

Kazuto Hirata National Institute for Materials Science, Tsukuba, Japan

Lutfi Ozyuzer Izmir Institute of Technology, Izmir, Turkey

Mahmoud Gaafar Menoufiya University, Egypt

Mehmet Canturk Turgut Ozal University, Turkey

Ming He University of Nankai, China

Özden Aslan Çataltepe Gedik University, Turkey

Said Sakhi American University of Sharjah, UAE

Takeshi Hatano National Institute for Materials Science, Tsukuba, Japan

Yilmaz Simsek Universität Erlangen-Nürnberg, Germany



8

Mohammad R. Kolahchi Institute for Advanced Studies in Basic Sciences, Iran

Mutlu Yaman Izmir Institute of Technology, Izmir, Turkey

Ozlem Bilgili Dokuz Eylül University, Izmir, Turkey

Rajneesh Mohan Jeju National University, Repulic of Korea

S. Saini Jeju National University, Repulic of Korea

Said Sakhi American University of Sharjah, UAE

Sebnem Yazici Izmir Institute of Technology, Izmir, Turkey

Yasemin Demirhan Izmir Institute of Technology, Izmir, Turkey



9

CONTENT

CONFERENCE PROGRAM

INVITED SPEAKERS

Quantum Terahertz Electronics (QTE) Using Coherent Radiation from High

Temperature Superconductor Bi2Sr2CaCu2O8+δ Intrinsic Josephson Junctions

(IJJ’s) Kazuo Kadowaki, Manabu Tsujimoto, Kaveh Delfanazari, Takeo Kitamura, Masashi

Sawamura, idehiro Asai, Takanari Kashiwagi, Hidetoshi Minami and Richard A.

Klemm ..................................................................................................................................... 24

Terahertz Emission of Intrinsic Josephson Junctions at High Bias and Low Bias

Regimes Huabing Wang, Jie Yuan, Mengyue Li, Jun Li, Akira Iishi, Takeshi Hatano, Peiheng

Wu, Boris Gross, Stefan Guénon, Dieter Koelle, Reinhold Kleiner ....................................... 25

Radiation characteristics on single crystalline Bi2Sr2CaCu2O8+δ mesa structures T. Kashiwagi, M. Tsujimoto, T. Yamamoto, H. Minami, K. Delfanazari, T.

Kitamura, M. Sawamura, K. Ishida, S. Sekimoto, C. Watanabe, K. Ivanovic, H. Asai,

M. Tachiki, R. A. Klemm, and K. Kadowaki .......................................................................... 26

Terahertz Wave Emission from Bi-2212 Thin Films Intrinsic Josephson

Junctions with Mesa/Step Edge Hybrid Structure Kensuke Nakajima, J. Yuan, R. Koshiya, J. Li, H. B. Wang, H. Yamada and A.

Hatano ...................................................................................................................................... 27

Theory for Josephson Plasma and Terahertz Radiation of Intrinsic Josephson

Junctions Xiao Hu .................................................................................................................................... 28

Numerical Study for Electromagnetic Wave Emission from Intrinsic Josephson

Junction Stacks with a Dielectric Cover Tomio Koyama, H. Matsumoto, Y. Ota, and M. Machida ...................................................... 29

Pattern Formation in Intrinsic Josephson Junctions and Terahertz Radiation Shi-Zeng Lin, Lev N. Bulaevaskii and Xiao Hu...................................................................... 30

Microwave emission from Josephson junctions - GHz to THz N.F. Pedersen ........................................................................................................................... 31

Hot Spot and THz Wave Generation in Bi2Sr2CaCu2O8 Intrinsic Josephson

Junction Stacks: Recent Developments Reinhold Kleiner, Boris Gross, Stefan Guénon, Dieter Koelle, Huabing Wang,

Mengyue Li, Jie Yuan, Akira Iishi, Takeshi Hatano, Zhenguo Jiang, Yangyin Zhong,

Peiheng Wu .............................................................................................................................. 32



10

Fundamental Aspects of c-axis Tunneling in Bi2Sr2CaCu2O8+δ Mesas and

Effects of Self Heating J.F. Zasadzinski, C. Kurter, L. Ozyuzer, K. E. Gray, T. Proslier, D.G. Hinks ........................ 33

Powerful coherent terahertz emission from Bi2Sr2CaCu2O8+ mesa array T. M. Benseman, K. E. Gray, A. E. Koshelev, W.-K. Kwok, U. Welp, H. Minami, K.

Kadowaki, and T. Yamamoto .................................................................................................. 34

Coherent Emission of Niobium Junctions: Recent Results Alexander M. Klushin, M. Galin, V.V. Kurin, A.D. Semenov, F. Müller, T. Scheller,

F. Song ..................................................................................................................................... 35

Modeling the THz Emission Patterns from Bi2Sr2CaCu2O8+δ Mesas of Various

Shapes Richard A. Klemm, Kazuo Kadowaki, Erica LaBerge, Candy Reid, Dustin Morley,

Manabu Tsujimoto, Takanari Kashiwagi, and Kaveh Delfanazari .......................................... 36

Three-dimensional simulation of THz radiation emitted from Intrinsic

Josephson junctions with hot spots Hidehiro Asai, M. Tachiki and K. Kadowaki .......................................................................... 37

Terahertz Wave Emitting From Flux-Flow Oscillators and Long Josephson

Junctions of a Complex Shape D. R.Gulevich, H. Farhan-Hassan, P. N. Dmitriev, V. P. Koshelets, F. V. Kusmartsev ......... 38

Vortex Lattice Transformations in Multiband superconductors--A case study of

MgB2-- Kazushige Machida, Tomoya Hirano, and Masanori Ichioka ................................................. 40

Gate Tuning of Macroscopic Quantum Phenomena in Graphene-Based

Josephson Junctions Gil-Ho Lee, Dongchan Jeong, Jae-Hyun Choi, Yong-Joo Doh, and Hu-Jong Lee ................. 41

Phenomenological Models of Layered Superconductors Richard A. Klemm ................................................................................................................... 42

Intrinsic flux of correlated electrons and holes for deepening in Intrinsic

Josephson effects M. Saglam and Z. Saglam........................................................................................................ 43

Get over Terrible Disasters from Earthquake and Tsunami

Tsutomu Yamashita ................................................................................................................. 44

Effect of thermal inhomogeneity of intrinsic Josephson junction stack for

excitation of synchronized terahertz Josephson plasma oscillations I. Kakeya, Y. Omukai, N. Hirayama, S. Mizuta, and M. Suzuki ............................................ 45

Coherent generation of phonon-polaritons in Bi-2212 intrinsic Josephson

junctions

Sven-Olof Katterwe, Holger Motzkau, Andreas Rydh and Vladimir Krasnov ....................... 45



11

Increasing THz Radiation Power and Monotonicity Using Optically Induced

Photonic Crystal in Layered Superconductors Alireza Kokabi, H. Kamrani, M. Fardmanesh ......................................................................... 47

Superconducting Properties of K-doped Fullerene Nanowhiskers Y. Takano, H. Takeya, T. Ozaki, H. Okazaki, T. Yamaguchi, R. Kato, T. Wakahara,

and K. Miyazawa ..................................................................................................................... 48

Carrier Doping of Intrinsic Josephson Junctions by c-axis Current Injection Paul Müller .............................................................................................................................. 49

Phase Diffusion in Intrinsic Josephson Junctions P. A. Warburton, J. C. Fenton, S. Saleem, T. A. Wootton, L. D. Ward and S. M. I.

Rizvi ......................................................................................................................................... 50

Comparison of phase slippage processes in Josephson junctions and in charge

density wave stacked junctions Yu.I. Latyshev .......................................................................................................................... 51

Josephson Effects in Topological Insulator Nanoribbons Yong-Joo Doh .......................................................................................................................... 52

Revisit to Terahertz Wave Emission with Motions of Josephson Vortices Hideki Matsumoto, T. Koyama, M. Machida and Y. Ota ....................................................... 53

Quantum Phases in Intrinsic Josephson Junctions:

Quantum Magnetism Analogy M. Machida, K. Kobayashi,

Y.Ohta, and T.Koyama ............................................................... 54

Current Voltage Characteristics and Resonance Features of Coupled Josephson

Junctions Yury Shukrinov, Mahmoud Gaafar, Ilhom Rahmonov, Kirill Kulikov, Mohammad

Hamdipour, Mohammad R. Kolahchi, Andre Both, Minoru Suzuki, Eman Hamza,

Khaled Hegab, Abdelhamid Galal, Hazem Abdelhafiz, Karim Elgamma, Ahmed

Foda ......................................................................................................................................... 55

Phase diagram of frustrated proximity sandwich composed of s and s±

superconductors A. E. Koshelev and V. Stanev ................................................................................................. 56

Synchronization in mesa array by radiation field inside base crystal

A. E. Koshelev ......................................................................................................................... 57

TALKS

Detection of Terahertz Waves from High Temperature Superconducting

Bi2Sr2CaCu2O8+δ L. Ozyuzer, Y. Demirhan, F. Turkoglu, H. Saglam, H. Koseoglu, H. Alaboz,

K. Kadowaki, Y. Simsek, P. Müller ........................................................................................ 59



12

Current induced lock-in phenomena in Y-123 and Bi-2212 IJJs under layer

parallel magnetic field Takeshi Hatano and Huabing Wang ........................................................................................ 60

New Lock-in Phenomena in Intrinsic Joesphson Junctions of Bi2Sr2CaCu2O8+δ

with Hole-Array K. Hirata, S. Ooi and T. Mochiku ............................................................................................ 61

Superconductivity induced by carrier injection into non-superconducting

Bi2Sr2CaCu2O8 Y. Simsek, Y. Koval, X. Y. Jin, S. Probst, C. Steiner, P. Müller

........................................... 62

Millimeter-Wave Emitting from Intrinsic Josephson Junctions Fabricated with

Misaligned Tl2Ba2CaCu2O8 Thin Film P. Wang, M. He, W. Xie, X. J. Zhao, X. Zhang, L. Ji, L. Fang and S.L.Yan ......................... 63

Effect of Microwave Irradiation on Parametric Resonance in Intrinsic

Josephson Junctions Mahmoud Gaafar, Yury Shukrinov, and Ahmed Foda ............................................................ 64

THz emission and response of intrinsic Josephson junctions Akinobu Irie, Dai Oikawa, Koichi Tamura, Kazuhiro Yamaki, Gin-ichiro Oya .................... 65

Simultaneous Detection of THz Emission and Observation of LTSLM Images Jie Yuan, Mengyue Li, Jun Li, Stefan Guénon, Boris Gross, Akira Ishii, Takeshi

Hatano, Peiheng Wu, Dieter Koelle, Reinhold Kleiner, Huabing Wang ................................ 66

An Investigation of the Effect of Grain Size on Some Properties of Intrinsic

Josepson Junction Özden Aslan Çataltepe, Zeynep Güven Özdemir and Ülker Onbaşlı ..................................... 67

Dynamics of resistively shunted Josephson junction (RSJ) under the influence of

second harmonics Mehmet Canturk, Iman N. Askerzade ..................................................................................... 68

Vortex dynamics in self-dual Josephson junction arrays near the quantum

critical point Said Sakhi ................................................................................................................................ 69

POSTERS

Simulation of I-V Characteristics of Josephson Junction Arrays using RCLSJ

Model Jamal Akhtar Khan, Abdullah A. Aljumah, M. Shahabuddin ................................................. 71

Transformation of Longitudinal Plasma Wave to the Charge Density Waves

and Origin of the Branching in Intrinsic Josephson Junction Yury Shukrinov, Eman Hamza, Hazem Abdelhafiz, Khaled Hegab ....................................... 72



13

Hot Spots and THz waves in single crystal Bi2Sr2CaCu2O8 structures B. Gross, S. Guénon, M. Grünzweig, J. Yuan, M. Li, A. Iishi, T. Hatano, D. Koelle,

H.B. Wang and R. Kleiner ....................................................................................................... 73

Unconventional Gap Structures of Bi2Sr2CaCu2O8+δ Revealed from Intrinsic

Josephson Junction Tunneling Spectroscopy Minoru Suzuki

, Takashi Hamatani, Kenkichi Anagawa and Takao Watanabe ...................... 74

Explanation of the Meissner effect in Nano Josephson Junctions by the

Quantum Entanglement of the Landau States M. Saglam, L. G. Boussiakou, L. Babsail, S. Alsaleh and A. Al-Modlej ............................... 75

Optimal Condition for Strong Terahertz Radiation based on Intrinsic

Josephson Junctions Feng Liu, Shi-Zeng Lin, and Xiao Hu ..................................................................................... 76

Fabrication of standing bridge bolometer based on thinned single crystal of

Bi2212 A. Kokabi, A. Moftakharzadeh, H. Alaboz, L. Ozyuzer, N. Miyakawa, M.

Fardmanesh .............................................................................................................................. 77

Chaotic Features of Coupled Josephson Junctions Yury Shukrinov, Mohammad Hamdipour, Mohammad R. Kolahchi, André E. Botha,

Minoru Suzuki ......................................................................................................................... 78

Study of The Various Shapes of Mesas for Tunable, Coherent and Continuous

Terahertz Waves Emission in Intrinsic Josephson Junctions Bi2Sr2CaCu2O8+δ Kaveh Delfanazari, M. Tsujimoto, T. Kashiwagi, H. Asai, T. Yamamoto, M.

Sawamura, T. Kitamura, R. Nakayama, K. Ishida, H. Minami, R.A. Klemm, T.

Hattori, and K. Kadowaki ........................................................................................................ 79

Electro-resistance characteristics in Sm0.55Sr0.45MnO3 Rajneesh Mohan, S. Saini, S. J. Kim ....................................................................................... 80

Microwave responses in a-axis oriented Y123/Pr123 stacked junctions S. Saini, M. Mukaida, S.-J. Kim .............................................................................................. 81

Influence of LCR Shunting in Current-Voltage Characteristic of Intrinsic

Josephson Junctions Ilhom Rahmonov, Yury Shukrinov, Kirill Kulikov and Karim ElGammal ............................ 82


critical point Said Sakhi ................................................................................................................................ 83

Searching for Doping Level of High Temperature Superconducting

Bi2Sr2CaCu2O8+δ Crystals for Powerful THz Emission Yasemin Demirhan, F. Turkoglu, H. Saglam, H. Koseoglu, M. Minematsu, H. Araki,

N.Miyakawa, T. Yamamoto, K. Kadowaki, L. Ozyuzer ......................................................... 84



14

Terahertz Emission from Rectangular Mesa Structures of Superconducting

Bi2Sr2CaCu2O8+δ F. Turkoglu, L. Ozyuzer, H. Koseoglu, Y. Demirhan, Y. Simsek, S. Preu, D. Ploss, S.

Malzer, H. B. Wang, P. Müller ................................................................................................ 85

Reactive Ion Etching of Superconducting Bi2212 using PRʹ/Ta/PR and Ta/PR

mask for the THz Waves Emission Hasan Koseoglu, Fulya Turkoglu, Yasemin Demirhan, Lutfi Ozyuzer .................................. 86

Fabrication of Triple Mesa Structures from High Temperature

Superconducting Bi2Sr2CaCu2O8+δ (Bi2212) for Terahertz Emission Hilal Saglam, Y. Demirhan, H. Koseoglu, F. Turkoglu, H. Alaboz, K. Kadowaki, L.

Ozyuzer .................................................................................................................................... 87

The Wide Band Radar Absorbing Epoxy Composites with Metal Coated Glass-Fiber

Fabrics

M. D. Yaman, L. Ozyuzer, S. Kangal, M. Tanoglu..................................................................88

X-Ray Photoelectron Spectroscopic Analysis of HfO2/Hf/Si Multilayer Structure

Prepared by Radio Frequency Magnetron Sputtering A. Cantas, G. Aygun ................................................................................................................ 89

Electrical and Optical Properties of Large Area Grown ITO Sebnem Yazici, Ayten Cantas, Mutlu D. Yaman, Hasan Koseoglu, Hilal Saglam,

Gulnur Aygun and Lutfi Ozyuzer ............................................................................................ 90

Fabrication of Superconductive Bi2212 Hot Electron Bolometer H. Alaboz, H. Köseoğlu, A. Kokabi, M. Fardmanesh, N. Miyakawa, L. Ozyuzer

................ 91

Fabrication and Characterization of CZTS Absorber Layer on Titanium

Coated Ceramic for Solar Cells M. A. Olgar, H. Saglam, S. Yazici, A. Cantas, G. Aygun, E. Yanmaz, L. Ozyuzer ............... 92

Temperature Dependence of Ionic Conductivity in PVB/LiClO4

Halil Arslan, H. Saglam, M. D. Yaman, H. Koseoglu, H. Alaboz, G. Aygun, L. Ozyuzer

................................................................................................................................................. 92

Mechanical and Superconducting Properties of Ag-doped Bi-2223

Superconductors E. Burcu Cevizci, O. Bilgili, K. Kocabas ................................................................................ 94

The influence of Nb Addition on Properties of Bi-2223 Superconductors Ozlem Bilgili, E. B. Cevizci, K. Kocabaş ............................................................................... 95

Index



15

CONFERENCE PROGRAM

June 10, Sunday

08:45-09:00

09:00-09:25

09:25-09:50

09:50-10:15

10:15-10:40

10:40-11:00

11:00-11:25

11:25-11:50

11:50-12:15

12:15-12:40

12:40-13:20

13:20-14:00

14:00-14:25 Registration











19:30-20:30 DINNER

20:30-21:30

21:30-22:30 WELCOME COCKTAIL, SAND BAR RADISSON BLU 22:30-23:30



16

1st day-June 11, Monday

08:45-09:00

Opening Ceremony (Talk of IZTECH Rector Prof. Dr. Mustafa Güden)

THz Experiment (I) Chair: Lutfi Ozyuzer

09:00-09:25

Kazuo Kadowaki (invited 1)

Quantum Terahertz Electronics (QTE) Using Coherent Radiation from High

Temperature Superconductor Bi2Sr2CaCu2O8+δ Intrinsic Josephson Junctions

(IJJ’s)

09:25-09:50

Huabing Wang (invited 2)

Terahertz Emission of Intrinsic Josephson Junctions at High Bias and Low

Bias Regimes

09:50-10:15

Takanari Kashiwagi (invited 3) Radiation characteristics on single crystalline Bi2Sr2CaCu2O8+δ mesa

structures.

10:15-10:40

Kensuke Nakajima (invited 4)

Terahertz Wave Emission from Bi-2212 Thin Films Intrinsic Josephson

Junctions with Mesa/Step Edge Hybrid Structure

10:40-11:00

COFFEE BREAK

THz Theory (I) Chair: Alex Koshelev

11:00-11:25

Xiao Hu (invited 5)

Theory for Josephson Plasma and Terahertz Radiation of Intrinsic Josephson

Junctions

11:25-11:50

Tomio Koyama (invited 6)

Numerical Study for Electromagnetic Wave Emission from Intrinsic

Josephson Junction Stacks with a Dielectric Cover

11:50-12:15

Shi-Zeng Lin (invited 7)

Pattern Formation in Intrinsic Josephson Junctions and Terahertz Radiation

12:15-12:40

Niels F. Pedersen (invited 8)

Microwave emission from Josephson junctions - GHz to THz

12:40-14:00

LUNCH



17

THz Experiment (II) Chair: Kazuo Kadowaki

14:00-14:25

Reinhold Kleiner (invited 9)

Hot Spot and THz Wave Generation in Bi2Sr2CaCu2O8+δ Intrinsic Josephson

Junction Stacks: Recent Developments

14:25-14:50

John F. Zasadzinski (invited 10)

Fundamental Aspects of c-axis Tunneling in Bi2Sr2CaCu2O8+δ Mesas and

Effects of Self Heating

14:50-15:15

Tim M. Benseman (invited 11)

Powerful coherent terahertz emission from Bi2Sr2CaCu2O8+d mesa array

15:15-15:40

Alexander M. Klushin (invited 12)

Coherent Emission of Niobium Junctions: Recent Results

15:40-16:00

COFFEE BREAK

Contributed Talk (I) Chair: John F. Zasadzinski

16:00-16:20

Lutfi Ozyuzer (talk 1)

Detection of Terahertz Waves from High Temperature Superconducting

Bi2Sr2CaCu2O8+δ

16:20-16:40

Takeshi Hatano (talk 2)

Current induced lock-in phenomena in Y-123 and Bi-2212 IJJs under layer

parallel magnetic field

16:40-17:00

Kazuto Hirata (talk 3)

New Lock-in Phenomena in Intrinsic Joesphson Junctions of

Bi2Sr2CaCu2O8+δ with Hole-Array

17:00-17:20

Yilmaz Simsek (talk 4)

Superconductivity induced by carrier injection into non-superconducting

Bi2Sr2CaCu2O8

17:20-17:40

Ming He (talk 5)

Millimeter-Wave Emitting from Intrinsic Josephson Junctions Fabricated

with Misaligned Tl2Ba2CaCu2O8 Thin Film

17:40-18:00

Mahmoud Gaafar (talk 6)

Effect of Microwave Irradiation on Parametric Resonance in Intrinsic

Josephson Junctions

19:30-20:30

DINNER

20:30-22:30

POSTER SESSION



18

2nd day-June 12, Tuesday

THz Theory (II) Chair: Xiao Hu

09:00-09:25

Richard A. Klemm (invited 13)

Modeling the THz Emission Patterns from Bi2Sr2CaCu2O8+δ Mesas of

Various Shapes

09:25-09:50

Hidehiro Asai (invited 14)

Three-dimensional simulation of THz radiation emitted from Intrinsic

Josephson junctions with hot spots

09:50-10:15

Fedor V. Kusmartsev (invited 15)

Terahertz Wave Emitting From Flux-Flow Oscillators and Long Josephson

Junctions of a Complex Shape.

10:15-10:40

Kazushige Machida (invited 16)

Vortex Lattice Transformations in Multiband superconductors --A case study

of MgB2--

10:40-11:00

COFFEE BREAK

Special Josephson Section Chair: Reinhold Kleiner

11:00-11:25

Hu-Jong Lee (invited 17)

Gate Tuning of Macroscopic Quantum Phenomena in Graphene-Based

Josephson Junctions

11:25-11:50

Richard A. Klemm (invited 18)

Modeling the THz Emission Patterns from Bi2Sr2CaCu2O8+δ Mesas of

Various Shapes

11:50-12:15

Ziya Saglam (invited 19)

Intrinsic flux of correlated electrons and holes for deepening in Intrinsic

Josephson effects

12:15-12:40

Tsutomu Yamashita (invited 20)

Get Over Terrible Disasters from Earthquake and Tsunami

12:40-14:00

LUNCH

14:00-18:00

EPHESUS TOUR

19:30-20:30

20:30-23:30

GALA DINNER, RADISSON BLU RESORT & SPA



19

3rdday-June 13, Wednesday

THz Experiment (III) Chair: Paul Müller

09:00-09:25

Itsuhiro Kakeya (invited 21)

Effect of thermal inhomogeneity of intrinsic Josephson junction stack for

excitation of synchronized terahertz Josephson plasma oscillations

09:25-09:50

Vladimir Krasnov (invited 22)

Coherent generation of phonon-polaritons in Bi-2212 intrinsic Josephson

junctions

09:50-10:15

Mehdi Fardmanesh (invited 23)

Increasing THz Radiation Power and Monotonicity Using Optically Induced

Photonic Crystal in Layered Superconductors

10:15-10:40

Yoshihiko Takano (invited 24)

Superconducting Properties of K-doped Fullerene Nanowhiskers

10:40-11:00

COFFEE BREAK

Josephson Junctions Chair: Huabing Wang

11:00-11:25

Paul Müller (invited 25)

Carrier Doping of Intrinsic Josephson Junctions by c-axis Current Injection

11:25-11:50

Paul A. Warburton (invited 26)

Phase Diffusion in Intrinsic Josephson Junctions

11:50-12:15

Yuri I. Latyshev (invited 27)

Comparison of phase slippage processes in Josephson junctions and in charge

density wave stacked junctions

12:15-12:40

Yong-Joo Doh (invited 28)

Josephson Effects in Topological Insulator Nanoribbons

12:40-14:00

LUNCH

Theory / Experiment (III) Chair: Takeshi Hatano

14:00-14:25

Hideki Matsumoto (invited 29)

Revisit to Terahertz Wave Emission with Motions of Josephson Vortices

14:25-14:50

Masahiko Machida (invited 30)

Quantum Phases in Intrinsic Josephson Junctions: Quantum Magnetism

Analogy



20

14:50-15:15

Yury Shukrinov (invited 31) Current Voltage Characteristics and Resonance Features of Coupled

Josephson Junctions

15:15-15:40

Alex E. Koshelev (invited 32)

Phase diagram of frustrated proximity sandwich composed of s and s±

superconductors

15:40-16:00

COFFEE BREAK

Contributed Talk (II) Chair: Paul A. Warburton

16:00-16:20

Akinobu Irie (talk 7)

THz emission and response of intrinsic Josephson junctions

16:20-16:40

Jie Yuan (talk 8)

Simultaneous Detection of THz Emission and Observation of LTSLM Images

16:40-17:00

Özden Aslan Çataltepe (talk 9)

An Investigation of the Effect of Grain Size on Some Properties of Intrinsic

Josepson Junction

17:00-17:20

Mehmet Canturk (talk 10)

Dynamics of resistively shunted Josephson junction (RSJ) under the influence

of second harmonics

17:20-17:40

Said Sakhi (talk 11)


critical point

17:40-18:00

CONCLUDING REMARKS

19:30-20:30

DINNER



21

POSTERS

Jamal Akhtar Khan

Simulation of I-V Characteristics of Josephson Junction Arrays using RCLSJ Model

Hazem Abdelhafiz

Transformation of Longitudinal Plasma Wave to the Charge Density Waves and Origin of

the Branching in Intrinsic Josephson Junction

Boris Gross

Hot Spots and THz waves in single crystal Bi2Sr2CaCu2O8 structures

Minoru Suzuki

Unconventional Gap Structures of Bi2Sr2CaCu2O8+δ Revealed from Intrinsic Josephson

Junction Tunneling Spectroscopy

Mesude Saglam

Explanation of the Meissner effect in Nano Josephson Junctions by the Quantum

Entanglement of the Landau States

Feng Liu

Optimal Condition for Strong Terahertz Radiation based on Intrinsic Josephson Junctions

Alireza Kokabi

Fabrication of standing bridge bolometer based on thinned single crystal of Bi2212

Mohammad R. Kolahchi

Chaotic Features of Coupled Josephson Junctions

Kaveh Delfanazari

Study of The Various Shapes of Mesas for Tunable, Coherent and Continuous Terahertz

Waves Emission in Intrinsic Josephson Junctions Bi2Sr2CaCu2O8+δ

Rajneesh Mohan (S.-J. Kim)

Electro-resistance characteristics in Sm0.55Sr0.45MnO3

Ilhom Rahmonov

Influence of LCR Shunting in Current-Voltage Characteristic of Intrinsic Josephson

Junctions

S. Saini

Microwave responses in a-axis oriented Y123/Pr123 stacked junctions

Said Sakhi

Vortex dynamics in self-dual Josephson junction arrays near the quantum critical point.



22

Yasemin Demirhan Searching for Doping Level of High Temperature Superconducting Bi2Sr2CaCu2O8+δ

Crystals for Powerful THz Emission

Fulya Turkoglu

Terahertz Emission from Rectangular Mesa Structures of Superconducting Bi2Sr2CaCu2O8+δ

Hasan Koseoglu

Reactive Ion Etching of Superconducting Bi2212 using PRʹ/Ta/PR and Ta/PR mask for the

THz Waves Emission

Hilal Saglam

Fabrication of Triple Mesa Structures from High Temperature Superconducting

Bi2Sr2CaCu2O8+δ (Bi2212) for Terahertz Emission

Mutlu Yaman

The Wide Band Radar Absorbing Epoxy Composites with Metal Coated Glass-Fiber Fabrics

Ayten Cantas

X-Ray Photoelectron Spectroscopic Analysis of HfO2/Hf/Si Multilayer Structure Prepared

by Radio Frequency Magnetron Sputtering

Sebnem Yazici

Electrical and Optical Properties of Large Area Grown ITO

Hakan Alaboz

Fabrication of Superconductive Bi2212 Hot Electron Bolometer

M. Ali Olgar Fabrication and Characterization of CZTS Absorber Layer on Titanium Coated Ceramic for

Solar Cells

Halil Arslan Temperature Dependence of Ionic Conductivity in PVB/LiClO4

Burcu Cevizci

Mechanical and Superconducting Properties of Ag- doped Bi-2223 Superconductors

Özlem Bilgili

The influence of Nb Addition on Properties of Bi-2223 Superconductors



23

INVITED SPEAKERS



24

Quantum Terahertz Electronics (QTE) Using Coherent Radiation

from High Temperature Superconductor Bi2Sr2CaCu2O8+δ

Intrinsic Josephson Junctions (IJJ’s)

Kazuo Kadowakia,b,c*

, Manabu Tsujimotob,c

, Kaveh Delfanazarib,c

, Takeo Kitamurab,c

,

Masashi Sawamurab,c

, idehiro Asaia,b

, Takanari Kashiwagia,b,c

, Hidetoshi Minamia,b,c

and

Richard A. Klemmd

aDivision of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba,

1-1-1, Tennodai Tsukuba, Ibaraki 305-8573 Japan b CREST-JST & WPI-MANA at NIMS

c Graduate School of Pure & Applied Sciences, University of Tsukuba

1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573, Japan d Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL

32816-2385

*Corresponding author

E-mail address: [email protected]

Phone: +81-29-853-5291, Fax: +81-29-853-4490

[keywords] Quantum Terahertz Electronics, Intrinsic Josephson Junctions, terahertz waves.

After the first observation of THz emission of electromagnetic waves (EMW’s) from the mesa

fabricated from single crystals of a high temperature superconductor Bi2Sr2CaCu2O8+δ, which is

comprised of a stack of densely packed many intrinsic Josephson junctions, a great deal of researches

have been performed concerning not only the fundamental issues of the radiation mechanism but also

a variety of applications such as noninvasive sensing, imaging, all kinds of spectroscopy across a vast

area of physics and chemistry, medical, biological, pharmaceutical sciences and technologies, security

issues, public and military surveillance, environmental monitors, high frequency high density

communications, etc. The basic principle working there obtaining THz EMW’s is nothing but the ac-

Josephson effect confirmed by the experimental results[1], and it is simply another synonymous

expression of emission of light in a quantum mechanics. The subjects dealt with above require both

new scientific and technological paradigm to work, named here as an academic nomenclature of

“Quantum Terahertz Electronics (QTE). In this presentation, the QTE is argued in comparison with

already established fields in both microwave and optical frequencies.

[1]. M. Tsujimoto et al., Phys. Rev. Lett. accepted for publication.



25

Terahertz Emission of Intrinsic Josephson Junctions at High Bias

and Low Bias Regimes

Huabing Wanga,b,*

, Jie Yuana,c

, Mengyue Lia,b

, Jun Lia,d

, Akira Iishia, Takeshi Hatano

a,

Peiheng Wub, Boris Gross

e, Stefan Guénon

e, Dieter Koelle

e, Reinhold Kleiner

e

a National Institute for Materials Science, Tsukuba, Japan

b Nanjing University, Nanjing, China

c Wuhan University of Science and Technology, Wuhan, China

d Hokkaido University, Sapporo, Hokkaido, Japan

e Physikalisches Institut and Center for Collective Quantum Phenomena in LISA

+, University of

Tübingen, Tübingen, Germany



Phone: +81-29-8592360, Fax: +81-29-8592801

[keywords] Intrinsic Josephson Junctions, terahertz waves.

Terahertz emission from intrinsic Josephson junctions made of the high temperature superconductor

Bi2Sr2CaCu2O8+ have been obtained both at low bias and high bias regimes [1, 2]. In the last couple of

years we have investigated THz electromagnetic wave generation in intrinsic junction stacks with

various structures, using a combination of transport measurement, direct electromagnetic wave

detection and low temperature scanning laser microscopy (LTSLM). Many efforts have been paid to

improve the frequency tunability and the power output of intrinsic Josephson junctions by using

different structures like conventional mesa structure, insular structure, double-sided structure, arrays,

and so on. While the focus of Reinhold Kleiner’s talk will be on the hot spot formation and the wave

formation in the high bias regime [2-4], I will review the THz emission properties of a variety of

samples, with a focus on the difference between high-bias and low-bias regimes.

*This research is supported by the DFG/JST Japanese-German Cooperative Program

"Nanoelectronics" via the project "Terahertz electronics on the atomic scale using intrinsic Josephson

junctions in cuprate superconductors".

References

[1] L. Ozyuzer, A. E. Koshelev, C. Kurter, N. Gopalsami, Q. Li, M. Tachiki, K. Kadowaki, T.

Yamamoto, H. Minami, H. Yamaguchi, T. Tachiki, K. E. Gray, W.-K. Kwok, U. Welp Science 318,

1291 (2007).

[2] H. B. Wang, S. Guénon, B. Gross, J. Yuan, Z. G. Jiang, Y. Y. Zhong, M. Grünzweig, A. Iishi, P.

H. Wu, T. Hatano, D. Koelle, R. Kleiner, Phys. Rev. Lett. 105, 057002 (2010).

[3] H. B. Wang, S. Guénon, J. Yuan, A. Iishi, S. Arisawa, T. Hatano, T. Yamashita, D. Koelle, and

R. Kleiner, Phys. Rev. Lett., 102 017006, (2009).

[4] S. Guénon, M. Grünzweig, B. Gross, J. Yuan, Z. G. Jiang, Y. Y. Zhong, M. Y. Li, A. Iishi, P. H.

Wu, T. Hatano, R. G. Mints, E. Goldobin, D. Koelle, H. B. Wang, and R. Kleiner, Phys. Rev. B 82,

214506 (2010).



26

Radiation characteristics on single crystalline Bi2Sr2CaCu2O8+δ

mesa structures

T. Kashiwagia,b,c

, M. Tsujimotoa,b,c

, T. Yamamotod, H. Minami

a,b,c, K. Delfanazari

a,b,c,

T. Kitamuraa,b,c

, M. Sawamuraa,b,c

, K. Ishidaa,b,c

, S. Sekimotoa,b,c

, C. Watanabea,b,c

,

K. Ivanovica,b,c

, H. Asaia,b,c

, M. Tachikia,b,c

, R. A. Klemme, and K. Kadowaki

a,b,c

a University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan

b CREST-JST, Kawaguchi, Saitama 332-0012, Japan

c International Center for Materials Nanoarchitectonics Satellite (WPI-MANA),

Tsukuba, Ibaraki 305-0044, Japan d Quantum Beam Science Directorate, Japan Atomic Energy Agency,

Takasaki, Gunma 370-1292, Japan e Department of Physics, University of Central Florida, Orlando, FL 32816, U.S.A.



Phone: +81-298-53-8803, Fax: +81-298-53- 4490

[keywords] Bi2212 single crystal, Intrinsic Josephson Junctions, terahertz waves.

In general, small, continuous, high-powered and stable solid state sources in the terahertz (THz)

frequency range have been desired for applications. The emitter based on the high temperature

superconductor Bi2Sr2CaCu2O8+δ (Bi2212) single crystal may satisfy these requirements in the THz

frequency region. Furthermore, it is emphasized that the operational principle of this device is entirely

different from the conventional ones available previously such as semiconductor devices and optical

devices, etc., since the ac-Josephson effect works in the intrinsic Josephson Junctions (IJJs) in Bi2212

single crystals.[1]

The continuous and coherent electromagnetic waves (EMWs) at THz frequencies with a power of a few μW can be generated from mesa structures of single crystalline Bi2212.

[2-4] The emission

frequency has been understood to follow two conditions simultaneously: the ac-Josephson effect fac =

(2e / h)V, where V is the dc-voltage, h is Plank’s constant, e is the elementary charge of an electron,

and the cavity resonance condition fca = c0/(2nw),where w is the width of the rectangular mesa, n is the

refractive index, and c0 is the speed of light in vacuum. We have studied shape, size and temperature

effect for the emission characteristics of Bi2212 mesa structures.[6]

The obtained results for radiation

fraquencies strongly suggest that the cavity resonance condition may be not primarily important for

determination of the frequency but the ac-Josephson effect may be responsible for the emission of

EMWs from the mesas. Recently, in order to understand the detail of radiation characteristics, we have

tried to measure radiation linewidth by using a mixer-circuit system. These experimental results will

be discussed in the conference.

References

[1] R. Kleiner and P. Müller, Phys. Rev. B 49, 1327 (1994).

[2] L. Ozyuzer et al, Science 318, 1291 (2007).

[3] M. Minami et al, Appl. Phys. Lett. 95, 232511 (2009). [4] K. Kadowaki et al, J. Phys. Soc. Jpn. 79, 023703 (2010). [5] M. Tsujimoto et al, Phys. Rev. Lett. 105, 037005 (2010).

[6] T. Kashiwagi et al, Jpn J. Appl. Phys. 51 010113 (2012).



27

Terahertz Wave Emission from Bi-2212 Thin Films Intrinsic

Josephson Junctions with Mesa/Step Edge Hybrid Structure

Kensuke Nakajimaa,*

, J. Yuanb, R. Koshiya

a, , J. Li

b, H. B. Wang

b, H. Yamada

a

and A. Hatanob

a Graduate School of Science and Engineering, Yamagata University, Yonezawa, 992-8510, Japan

b National Institute for Materials Science, Tsukuba, Japan



Phone: +81-238-26-3291

[keywords] Intrinsic Josephson Junctions, terahertz, thin films.

Since the discovery of the intrinsic Josephson effect[1], it admits of no argument that the

prospective application would be a terahertz generator. Accordingly, the first monotonic terahertz light

emitted from the Josephson plasma resonant Bi-2212 mesa junctions attract our attentions entirely.

Since then, follow up studies has replicated emissions, however, there still remain ambiguities in the

emission mechanism. Besides studies on the mechanism, engineering studies on device design

including material developments is also important from application point of view. We have develop

thin film Bi-2212 intrinsic Josephson junctions specific in a hybrid structure consisting of mesa on

step edge part of junction. The I-V characteristic of the hybrid junctions reveals an IC stair and a clear

break point due to the mesa and step edge junction, respectively. Although the I-V characteristics

present two group of branches distinct from IC each other, the Josephson relation V=0f was satisfied

at the bias voltage of terahertz emission assuming that whole junctions were equally biased through

the mesa part to step edge part. Terahertz wave frequency was also consistent of the half wave

resonance of the junction width. We claims that the thin film terahertz emitting IJJ has a bright aspect

of developing the high power device.

*This work was supported in part by a Grant-in-Aid for Scientific Research B (No.20360151) from the

Japan Society for the Promotion of Science (JSPS). A part of this work was carried out in the clean

room of Yamagata University.

Structure of the hybrid IJJ Typical I-V property and emission of the hybrid IJJ

References

[1] R. Kleiner and P. Müller, Phys. Rev. B 49, 1327 (1994).




28

Theory for Josephson Plasma and Terahertz Radiation of

Intrinsic Josephson Junctions

Xiao HU

International Center for Materials Nanoarchitectonics (WPI-MANA)

National Institute for Materials Science (NIMS), Tsukuba, Japan



Phone: +81-29-8604897, Fax: +81-29-8604706

[keywords] Intrinsic Josephson junction, sine-Gordon equation, cavity resonance, terahertz waves.

Inspired by the successful excitation of coherent THz electromagnetic waves from the BSCCO

mesa [1], we have carried out theoretical investigation on the dynamics of superconductivity phase

and electromagnetic cavity phenomena in a stack of intrinsic Josephson junctions (IJJs) [2,3]. Solving

the sine-Gordon equations with huge inductive coupling, we found a state characterized by an

alternating stack of plus and minus pi phase kinks along the c axis. Rotated by the applied voltage due

to the ac Josephson effect, these pi kinks transform large energy in the form of dc current into cavity

electromagnetic oscillation via the nonlinearity of dc Josephson effect. The system behaves effectively

as a series of nano windmills.

In the talk we will report our recent progresses. First, we discuss the instability of sine-Gordon

system in cavity. We find a state with broken translational symmetry in the c axis of IJJs, which

evolves into the pi kink state at large inductive coupling constant, low cavity modes and strong cavity

resonance [4]. We then address the issue how to enhance the radiation power from IJJs. We propose a

system of tall stack of IJJs wrapped by a dielectric material, which has large radiation surface and

meanwhile exhibits cavity resonance. We find that, as a case of Jacobi law, there is an optimal

dielectric constant for a given stack, and derive the optimal radiation power per unit length in c axis in

terms of material parameters of the IJJs [5].

This is a collaboration with Feng Liu and Shi-Zeng Lin. The work was supported by WPI Initiative

on Materials Nanoarchitectonics, MEXT of Japan and by CREST-JST.

References:


[2] S.-Z. Lin and X. Hu, Phys. Rev. Lett. Vol.100, 247006 (2008).

[3] X. Hu and S.-Z. Lin, Supercond. Sci. Tech. Vol.23, 253001 (2010) [topical review]. [4] X. Hu and F. Liu, in preparation for submission.

[5] F. Liu, S.-Z. Lin and X. Hu, in preparation for submission.



29

Numerical Study for Electromagnetic Wave Emission from

Intrinsic Josephson Junction Stacks with a Dielectric Cover

Tomio Koyamaa,*

, H. Matsumotoa, Y. Ota

b, and M. Machida

c

a Institute for Materials Research, Tohoku University , Sendai,980-8577, Japan

bRiken, Wako, Japan

e CCSE, Japan Atomic Energy Agency, Kashiwa, Japan



Phone: +81-22-2152008, Fax: +81-22-2152006


Terahertz (THz) wave emission from intrinsic Josephson junction stacks (IJJ’s) was observed in Bi-

2212 mesas by Ozyuser et al [1]. The emission in the low-bias region takes place in the voltage state in

which the Josephson frequency reaches one of the electromagnetic cavity mode frequencies of the

mesas. We performed numerical simulations for the electromagnetic excitations in the system

composed of IJJ’s and the space surrounding the IJJ’s to clarify the mechanism of the emission and

also to design an efficient THz emission devise. In this talk I will present our recent numerical results

on the THz emission from the IJJ’s with a dielectric cover. In this simulation we use the xz-model [2],

which is a 2-dimensional model for IJJ’s located in a vacuum. It is shown that the n=2 cavity mode

(one wavelength mode) emission is greatly enhanced in the presence of a dielectric cover. This

enhancement is caused by the excitation of a solitonic mode. We also discuss the dynamical behavior

of the phase differences in the IJJ’s when the dielectric constant of the dielectric cover is changed.

*This research is supported by JST-CREST and KAKENHI(C).

References


[2] T. Koyama, H. Matsumoto, Y. Ota and M. Machida, Supercond. Sci. Technol. 24, 085007 (2011)



30

Pattern Formation in Intrinsic Josephson Junctions and Terahertz

Radiation

Shi-Zeng Lin1,*

, Lev N. Bulaevaskii1 and Xiao Hu

2

1 Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

2 WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba

305-0044, Japan



Phone: +1-505-664-0117, Fax: +1-505-665-2659

[keywords] Pattern formation, Intrinsic Josephson Junctions, terahertz waves.

Tremendous effect has been made to excite strong terahertz radiation from intrinsic Josephson

junctions (IJJs) in BSCCO cuprate superconductors [1, 2]. One possible direction is to use thick

sample with more radiating junctions. To achieve a strong radiation, it is important to understand the

dynamics of superconducting phase in thick samples.

We study the dynamics of superconducting phase in a stack of IJJs, using inductively coupled sine-

Gordon equation. We simulate IJJs stack with number of junctions up to N=10,000. We show that the

resistive state with superconducting phase homogenous along the ab-plance is always unstable due to

the instability, and complex patterns are then developed. The resulting patterns are characterized by

standing electromagnetic wave oscillations and phase jump along the ab-plane [3, 4]. The patterns

that are uniform and non-uniform along the c-axis compete with each other. The pattern uniform along

the c-axis supports strongest radiation. For a stack with large N, there are many patterns corresponding

to a single voltage. Thus it is difficult to excite the desired patterns simply by tuning voltage in

experiment. For a stack with small N, patterns can be selected by voltage because they are well

separated in frequency. We consider the case when IJJs stack is irradiated by weak electromagnetic

waves. We find that the irradiation can select the pattern uniform along the c-axis, which point a

possible way to achieve strong radiation in experiments.

References


[2] X. Hu and S. Z. Lin, Supercond. Sci. Technol. 23, 053001 (2010).

[3] S. Z. Lin and X. Hu, Phys. Rev. Lett. 100, 247006 (2008).

[4] A. E. Koshelev, Phys. Rev. B 78, 174509 (2008).



31

Microwave emission from Josephson junctions - GHz to THz

*N.F. Pedersen

Department of Mathematics DTU, Technical University of Denmark, DK-2800 Lyngby, Denmark



Phone: +45 45253089


Ever since the Josephson junction was discovered, the possibility of generating high frequency

radiation has been considered. Many different methods have been reported, such as the use of a cavity

or an impedance transformer, designing a clever microwave layout, or using an array or a stack of

Josephson junctions. Fluxon dynamics in long Josephson junctions is another method. The last two

ideas may be combined in stacked Josephson junctions of the BSCCO type that are particularly

interesting since the power of the emitted radiation even at THz frequences may scale with the number

of junctions squared. Such radiation could have applications such as a local oscillator in an integrated

receiver, a spectrometer, an imaging device etc. The stack of inductively coupled long Josephson

junctions is modeled as a system of coupled sine-Gordon equations. The key point for oscillator

performance is to have in-phase coherent motion of fluxons in the different Josephson junctions in the

stack. This may be obtained by having all the junctions in the stack interacting with each other as well

as with a cavity. Such a system has similarity to other systems described by the socalled Kuramoto

theory for syncronisation of oscillators. The fluxon dynamics is very non-linear, and numerical

simulations are usually needed. A comparison with a much simpler system – a single Niobium

junction coupled to a cavity – is made. The role of a negative differential resistance for the radiation

emission will be discussed.



32

Hot Spot and THz Wave Generation in Bi2Sr2CaCu2O8 Intrinsic

Josephson Junction Stacks: Recent Developments

Reinhold Kleinera,*

, Boris Grossa, Stefan Guénon

a, Dieter Koelle

a, Huabing Wang

b,c,

Mengyue Lib,c

, Jie Yuanb, Akira Iishi

b, Takeshi Hatano

b, Zhenguo Jiang

c, Yangyin

Zhongc, Peiheng Wu

c,

a Physikalisches Institut and Center for Collective Quantum Phenomena in LISA

+, University of

Tübingen, Tübingen, Germany b

National Institute for Materials Science, Tsukuba, Japan c Nanjing University, Nanjing, China



Phone: +49-7071-2976315, Fax: +49-7071-295406


Stacks of intrinsic Josephson junctions made of the high temperature superconductor

Bi2Sr2CaCu2O8 have been shown to emit coherent radiation at THz frequencies [1]. Emission can

occur at relatively low bias but also at large input power. At high bias a hot spot and a standing wave,

formed in the “cold” part of the stack, coexist [2-4]. THz radiation is very stable in this regime,

exhibiting a linewidth which is much smaller than expected from a purely cavity-induced

synchronization. We investigate the interaction of hot spots and THz waves using a combination of

transport measurement, direct electromagnetic wave detection and low temperature scanning laser

microscopy (LTSLM). In this talk recent developments will be presented, with a focus on the

mechanism of hot spot formation.

*This research is supported by the DFG/JST Japanese-German Cooperative Program

"Nanoelectronics" via the project "Terahertz electronics on the atomic scale using intrinsic Josephson

junctions in cuprate superconductors"

References


[2] H. B. Wang, S. Guénon, J. Yuan, A. Iishi, S. Arisawa, T. Hatano, T. Yamashita, D. Koelle, and

R. Kleiner, Phys. Rev. Lett., 102 017006, (2009).

[3] S. Guénon, M. Grünzweig, B. Gross, J. Yuan, Z. G. Jiang, Y. Y. Zhong, M. Y. Li, A. Iishi, P. H.

Wu, T. Hatano, R. G. Mints, E. Goldobin, D. Koelle, H. B. Wang, and R. Kleiner, Phys. Rev. B 82,

214506 (2010).

[4] H. B. Wang, S. Guénon, B. Gross, J. Yuan, Z. G. Jiang, Y. Y. Zhong, M. Grünzweig, A. Iishi, P.

H. Wu, T. Hatano, D. Koelle, R. Kleiner, Phys. Rev. Lett. 105, 057002 (2010).



33

Fundamental Aspects of c-axis Tunneling in Bi2Sr2CaCu2O8+δ

Mesas and Effects of Self Heating

J.F. Zasadzinski*a

, C. Kurterb, L. Ozyuzer

c, K. E. Gray

d , T. Proslier

d, D.G. Hinks

d

a Department of Physics, Illinois Institute of Technology, Chicago, Illinois, USA 60616

bDepartment of Physics, University of Illinois, Urbana, Illinois 61801

c Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey

d Materials Science Division, Argonne National Laboratory, Illinois, USA 60439



Phone: 1-312-5675874, Fax: 1-312-5673494

[keywords] Intrinsic Josephson Junctions, tunneling

The detailed nature of c-axis electron tunneling in Bi2Sr2CaCu2O8+δ mesas has generally been

obscured by the presence of strong self heating. As self heating is reduced, either by intercalation of

the Bi2212 crystals or reduction in mesa volume, back bending of the current-voltage (I-V) curve is

eliminated and a regime of high, sharp conductance peaks is observed. It has been shown recently [1]

that the sharp peaks, while having the appearance of a superconducting gap, still constitute strong self

heating and it is only with further reduction of dissipation that the intrinsic quasiparticle density of

states (DOS) is revealed. The DOS is characterized by relatively broad peaks at the superconducting

gap voltage and a strong dip/hump feature, all on top of a normal state background that displays a

decreasing conductance with increasing bias voltage. These features are now consistent with

nominally c-axis, single junction methods such as STM and break junctions. The dip features appear

to originate from retardation effects in the pairing self-energy from the coupling of electrons to spin

fluctuations similar to the electron-phonon interaction in conventional superconductors. [2] The

conductance dip is a consequence of electron coupling to the resonance mode in the spin fluctuation

spectrum. The observation of the intrinsic DOS in mesas has provided insight into the tunneling matrix

element. Examination of the Josephson ICRN product and the quasiparticle conductance in the sub-gap

region has shown that the matrix element is neither purely coherent nor purely incoherent tunneling

but some mixture of both. Heating models will also be discussed. The effect of quasiparticle scattering

is incorporated into a phenomenological rate (T). This term reduces the backbending for uniform self

heating but does not eliminate it. A spatially non-uniform heating model improves agreement with the

experimental observations of sharp conductance peaks without backbending.

*Work supported by UChicago Argonne, LLC. Operator of Argonne National Laboraoty a U.S.

DOE Office of Science Labortory operated under contract No. DE-AC02-06CH11357 and TUBITAK

(Scientific and Technical Research Council of Turkey) project number 108T238. L.O. acknowledges

support from Turkish Academy of Sciences and Alexander von Humboldt Foundation.

References

[1] C. Kurter et al, Phys. Rev. B 81, 224518 (2010).

[2] O. Ahmadi et al, Phys. Rev. Lett. 106, 167005 (2011).



34

Powerful coherent terahertz emission from Bi2Sr2CaCu2O8+ mesa

array

T. M. Bensemana,*

, K. E. Graya, A. E. Koshelev

a, W.-K. Kwok

a, U. Welp

a,

H. Minamib, K. Kadowaki

b, and T. Yamamoto

c

a Materials Science Division, Argonne National Laboratory, Illinois, USA

b Institute for Materials Science, University of Tsukuba, Tsukuba, Japan

c Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki Gunma, Japan



Phone: +1-630-2526219, Fax: +1-630-2524748


There is rapidly growing interest in the generation of electromagnetic (EM) waves at terahertz

frequencies, because of their potential applications in novel nondestructive imaging and spectroscopy

in a wide range of settings. These include not only scientific applications, but also medical diagnostics,

high-bandwidth communication technologies, and security and defense purposes [1]. Compact, stable

and high-power sources of THz radiation are highly desirable for these applications. A variety of

technologies have been developed [1, 2]; nevertheless, the frequency range from 0.5 to 2 THz, the so-

called THz-gap, has been difficult to fill with solid-state sources. However, we have recently shown

that stacks of intrinsic Josephson junctions in the highly anisotropic high-Tc superconductor

Bi2Sr2CaCu2O8+ (Bi-2212) can be induced to emit coherent continuous-wave radiation in this

frequency range [3]. Our stacks were designed in such a way that an electromagnetic cavity resonance

synchronizes a large number of intrinsic Josephson junctions into a macroscopic coherent state.

While the radiated power scales as the square of the number of junctions oscillating in phase, in

practice the feasible number of junctions N for a single stack is limited by lithographic process

constraints, by the need to remove resistively generated heat, and by THz re-absorption phenomena in

tall stacks. For generating commercially useful levels of power it is thus highly advantageous to obtain

synchronized emission from multiple stacks [4]. Here we demonstrate 150 microwatts of radiation

power at 0.51 THz, using three synchronized stacks with N = 660 patterned on a single Bi-2212

crystal. The emitted power scales roughly as the square of the number of energized stacks, while the

total power spectrum is monochromatic to within observational limits. These results imply that the

stacks radiate coherently.

This research was funded by the Department of Energy, Office of Basic Energy Sciences, under

Contract No. DE-AC02-06CH11357.

References

[1] M. Tonouchi, Nature Photonics 1, 97 (2007).

[2] P. Shumyatsky, R. R. Alfano, J. Biomedical Optics 16, 033001 (2011).

[3] L. Ozyuzer et al., Science 318, 1291 (2007).

[4] N. Orita, H. Minami, T. Koike, T. Yamamoto, K. Kadowaki, Physica C 470, S786 (2010).



35

Coherent Emission of Niobium Junctions: Recent Results

Alexander M. Klushina,*

, M. Galina, V.V. Kurin

a, A.D. Semenov

b,

F. Müllerc, T. Scheller

c, F. Song

d

a Institute for Physics of Microstructures RAS, 603950 Nizhny Novgorod, Russia

bInstitute of Planetary Research, German Aerospace Centre (DLR), 12489 Berlin, Germany

c Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany d

Physics Institute III, University of Erlangen, Erlangen, Germany



Phone: +7-831-7507705, Fax: +7-831-7507707

[keywords] Josephson Junctions, terahertz waves.

The Josephson junctions are natural electrically pumped high-frequency oscillators. The relatively

small radiation power coupled off-chip can be increased by synchronizing large arrays of Josephson

junctions and improving impedance matching of the junctions to the open space [1]. The series

connected thin film niobium junctions could be synchronized to the resonances of the electromagnetic

field in the substrate in order to overcome the well-known impedance mismatch between the junctions

and the open space [2]. In this case the emission power substantially increases and it results in the

appearance of the self-induced current steps [3]. Coherent tunable non-Josephson radiation was

observed up to the frequency of 0.25 THz, and the maximum radiation power detected at room

temperature was nearly 7 μW around 0.143 THz. In our talk we focus on the discussing the

characteristics of the self-induced steps observed on current-voltage (I-V) curves of a series of

amorphous Nb-Si barrier junction arrays of different designs [4]. The second part of the talk will be

devoted to investigation of the directivity pattern of the array emission. The results achieved in our

experiments and numerical simulations of the electric field distribution on the surface of a silicon

substrate allowed us to suppose that optimizing of the circuits designs will lead to the increase the

frequency and power of Josephson radiation.

* This research is partially supported by the Russian Ministry of Education under the Federal

Program "Scientists and Science Educators of Innovative Russia in 2009-2013" and by the grants of

the Russian Foundation for Basic Research (RFBR).

References

[1] A. K. Jain et al, Physics Reports 109, 309 (1984).

[2] F. Song, F. Müller, R. Behr, A.M. Klushin, Appl. Phys. Lett. 95, 172501 (2009).

[3] F. Song, et al, Appl. Phys. Lett. 98, 142506 (2011).

[4] F. Song, et al, Superconductor Science and Technology, submitted for publication (2012).



36

Modeling the THz Emission Patterns from Bi2Sr2CaCu2O8+δ

Mesas of Various Shapes

Richard A. Klemma,*

, Kazuo Kadowakib#

, Erica LaBergea, Candy Reid

a, Dustin

Morleya, Manabu Tsujimoto

b#, Takanari Kashiwagi

b#, and Kaveh Delfanazari

b#

a Department of Physics, University of Central Florida, Orlando, FL 23816 USA

bInstitute of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba,

Tsukuba, Ibaraki 305-8573, Japan *Corresponding author


Phone: +1-407-882-1160, Fax: +1-407-823-5512

[keywords] Intrinsic Josephson Junctions, terahertz waves, angular distribution

From detailed studies of the angular dependence of the radiation from the inner and outer current-

voltage characteristic branches of Bi2Sr2CaCu2O8+ mesas of various shapes, it has become clear that

the primary radiation source is the dipole-like radiation that occurs by synchronizing the ac Josephson

radiation from at least a substantial fraction of the intrinsic Josephson junctions. In some cases, this

radiation can be enhanced by the excitation of an internal electromagnetic cavity, especially for thin

stand-alone mesas of either rectangular or circular shapes. Depending upon the cavity mode, the

combination of the resulting radiation can be either entirely coherent, or an incoherent mixture of

individually coherent synchronized ac Josephson radiation and the cavity radiation. In addition, for

triangular mesas and groove mesas in general, the radiation frequency is not fixed by the cavity

excitation, but can be widely tunable. In addition, the nature of the substrate is very important, as

superconducting and normal metallic substrates lead to substantially different radiation patterns. Two-

parameter fits to the experimental radiation patterns thin mesas of rectangular, circular, and isosceles

triangular shapes will be presented.

#This research is partially supported by CREST-JST (Japan Science Technology Agency), WPI

(World Premier International Research Center Initiative), MANA (Materials Nanoarchitechtonics)

projects (NIMS), and Strategic Initiative category (A) at the University of Tsukuba.

References

[1] R. A. Klemm and K. Kadowaki, J. Phys.: Condens. Matter 22, 375701 (2010).

[2] R. A. Klemm and K. Kadowaki, J. Super. Novel Magn. 23, 613 (2010) .

[3] R. A. Klemm et al., J. Phys.: Condens. Matter 23, 025701 (2011).

[4] K. Kadowaki et al., J. Phys. Soc. Jpn. 79, 023703 (2010).

[5] M. Tsujimoto et al., Phys. Rev. Lett. 105, 037005 (2010).

[6] T. Kashiwagi et al., J. Phys. Soc. Jpn. 80, 094709 (2011).

[7] T. Kashiwagi et al., Jap. J. Appl. Phys. 51, 010113 (2012).

[8] M. Tsujimoto et al., Phys. Rev. Lett. (2012) (in press).



37

Three-dimensional simulation of THz radiation emitted from

Intrinsic Josephson junctions with hot spots

Hidehiro Asai*, M. Tachiki and K. Kadowaki

Faculty of Pure and Applied Science, University of Tsukuba,

Ten-noudai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan



Phone: +81 (0)29 853 8802, Fax: +81 (0)29 853 8802

[keywords] Intrinsic Josephson Junctions, hot spot, terahertz waves.

High Tc superconductors have received attention as strong candidates for compact solid-state THz

source since Ozyuzer et al., reported radiation of coherent THz wave from Bi2Sr2CaCu2O8+δ (Bi2212)

single crystal[1]. The high-Tc superconductors, such as Bi2212, form intrinsic Josephson junctions

(IJJs), that is, natural stacks of Josephson junctions composed of the stacking of superconducting

CuO2 layers and insulating layers. Thus, the ac Josephson currents flow through the crystals under dc

bias voltages. Intense radiation has been reported in both experimental and theoretical studies at the

voltages where the ac Josephson frequencies coincide with cavity resonant frequencies of the Bi2212

mesa [2,3]. However, the precise nature of the radiation mechanism is not fully understood. In

particular, the effects of inhomogeneities on the radiation patterns emitted by IJJs have not been

investigated in previous studies. Recently, Wang et al., have reported the appearance of hot spots

where the temperature is locally high [4], and these inhomogeneities are considered to affect the

emission from the IJJs.

In this presentation, we present a three-dimensional simulation of the radiation from IJJs to discuss

the radiation properties of IJJs in further detail. In particular, we focus on the radiation properties of

the IJJs having a hot spot. We consider the appearance of a hot spot in the mesa where jc locally

decreases, and investigate the change of the radiation power with the positions of the hot spots. The

radiation power is calculated as a function of the voltage for three different hot spot positions. We

observe strong radiation when the ac Josephson frequency satisfies the cavity resonance condition.

Transverse magnetic modes TMm,n whose indices m and n are even appear regardless of the positions

of hot spots. On the other hand, TMm,n cavity modes whose m or n are odd appear only when the hot

spots break the reflectional symmetry of the mesa structure. Moreover, the radiation patterns emitted

from the IJJs reflect the coexistence of two types of internal modes, that is, the uniform background

mode and the cavity resonance mode. In particular, the radiation patterns for odd-numbered cavity

resonance conditions exhibit asymmetry because of the interference between these two types of

radiation waves. Furthermore, in the case of even-numbered cavity resonance conditions, the

interference between these two types of Josephson plasma modes induces asymmetric Fano-like peaks

in the radiation power vs. voltage curves.

*This research is partially supported by JST-CREST (Japan Science Technology Agency).

References


[2] K. Kadowaki et al., JPSJ 79, 023703 (2010).

[3] S. Lin and X. Hu, PRL 100, 247006 (2008).

[4] H. B. Wang et al., PRL 105, 057002 (2010).



38

Terahertz Wave Emitting From Flux-Flow Oscillators and Long

Josephson Junctions of a Complex Shape.

D. R.Gulevicha, H. Farhan-Hassan

a, P. N. Dmitriev

b, V. P. Koshelets

b,

F. V. Kusmartseva*

a

Department of Physics Loughborough University, LE11 3TU, UK, b

Kotel'nikov Institute of Radio Engineering and Electronics, Russian Academy of Science,

Moscow 125009, Russia



Phone: +44159223316, Fax: +441509223986


In present paper we have investigated properties of a new class of devices, which can be generally

names as Flux-Flow Oscillator (FFO) of a complicated shape. A search for tuneable sources of

coherent terahertz radiation or of T-rays is now at its culmination stage. If such sources will be

discovered they will have zillions applications in physics, astronomy, chemistry, biology and

medicine. Until very recently the search has been focused mostly on the usage and improvement of

quantum cascade lasers, however recently the Josephson junctions have attracted a strong attention.

For multi-connected Josephson junction, there may arise a fluxon cloning, the phenomenon predicted

theoretically in the Ref. [2-5]. In general, the fluxon cloning circuits provide the producing fluxon

without applied magnetic field, that is in a very different manner than conventional FFO developed

nowadays for practical applications [6]. It is worth noting that there are many interesting

configurations for a long Josephson junction such as overlap, inline and annular geometries. However,

the inline and annular structures are not suitable for application as flux flow oscillators (FFO).

Therefore, previous studies have used only overlap structure as FFOs operate by applying external

magnetic field. In this structure, there arise Fiske resonances which are associated with strong

emission of electromagnetic radiation. Recently, it was shown that the cloned vortices may be ordered

to form a train of fluxon, which is eventually operating as a flux flow oscillator created without

external magnetic field for annular geometry by means of T-junction. In this paper we will confine our

attention to study theoretically and experimentally how a fluxons cloning circuits can be used as a

FFO operating without external magnetic field from linear overlap geometry. Here we shown that the

tuneable sources of T-rays may be build up with the use of Josephson junctions of a complicated

shape, namely, the powerful and coherent T-rays may be generated by Flux Flow Oscillators made

with the use of flux cloning circuit, that can in principle operate even without magnetic field. Here we

have designed such a novel device and build it up with the use of superconductors forming the long

Josephson T-,Y- or any shaped junction of a linear overlap geometry made up with Nb-AlOx-Nb

technology[1]. We have theoretically described the properties of such a device and the dynamics of

vortices there. Finally we have tested the device experimentally and demonstrated that the flux cloning

can lead to a strong coherent terahertz radiation. The shapes of the spectral lines measured was very

narrow that opens a broad range of applications to detect variation of gas concentration in atmosphere,

to detect cancer cells and to build up a T-rays telescope and to use it in mapping of universe map in

the terahertz frequency range.



39

References

[1] R. A. Barone and G. Paterno, Physics and Applications of the Josephson Effect, John Wiley and

Sons, Inc. (1982).

[2] D.R.Gulevich, F.V. Kusmartsev, Phys Rev. Lett., 97, 017004, 2006

[3] D. .R.Gulevich, F.V. Kusmartsev, Supercond. Sci. Technol. 20, S60-S67, 2007

[4] H. Farhan-Hassan and F. V. Kusmartsev, Spontaneous Movable Semifluxon Generation-New

Phenomena in nano-electronic superconducting system, J. Phys.: Conf. Ser., 248, 012058, 2010.

[5] T. Nagatsuma, K. Enpuku, F. Irie, and K. Yoshida, J. Appl. Phys., 54, 3302, (1983),

[6] V. P. Koshelets et al, IEEE Trans. on Applied Superconductivity, 5, 3057, 1995.



40

Vortex Lattice Transformations in Multiband superconductors

--A case study of MgB2--

Kazushige Machida*, Tomoya Hirano, and Masanori Ichioka

Department of Physics, Okayama University, Okayama 700-8530, Japan



Phone: +81-86-2517814, Fax: +81-86-2517830

[keywords] Vortex lattice transformation, First principles band calculation, Eilenberger theory,

Multiband superconductors, MgB2.

Motivated by a recent small angle neutron diffraction experiment [1] on a typical multiband

superconductor MgB2, we develop a theory of the vortex lattice transformations based on microscopic

Eilenberger equation combined with density functional band calculation. This theoretical framework is

a truly microscopic first principles superconducting theory for mixed state with minimal adjustable

parameter.

Here in order to check the applicability and validity of this framework, we study the vortex lattice

phase diagram in field (H) and temperature (T) for MgB2 where H//(001) in the hexagonal crystal,

consisting of the three regions: The observed regular triangle lattices are oriented either along the a-

axis direction of the underlying crystal lattice (-phase), or along the b-axis (-phase), or the

intermediate direction between them (-phase). We examined the successive vortex lattice

transformations upon increasing T along the upper critical field and succeeded in

reproducing this successive transformation. The physical origin of the intriguing b-phase is argued to

be due to the competition of the Fermi surface topology between three dimensional p-band and two-

dimensional like s-band, that is, the Fermi velocity direction and angle resolved density of states.

This work forms one of our continuing efforts toward establishing a first principles microscopic

superconducting theory for mixed state in type II superconductors [2,3].

References

[1] P. Das, C. Rastovski, T. R. O’Brien, K. J. Schlesinger, C. D. Dewhurst, L. DeBeer-Schmitt, N. D.

Zhigaldo, J. Karpinski, and M. R. Eskildsen, Metastable vortex lattice phases in superconducting

MgB2 (preprint).

[2] K. M. Suzuki, K. Inoue, P. Miranovic, M. Ichioka, and K. Machida, J. Phys. Soc. Jpn., 79, 013702

(2010).

[3] H. M. Adachi, M. Ishikawa, T. Hirano, M. Ichioka, and K. Machida, J. Phys. Soc. Jpn., 79, 013702

(2011).



41

Gate Tuning of Macroscopic Quantum Phenomena in Graphene-

Based Josephson Junctions

Gil-Ho Leea, Dongchan Jeong

a, Jae-Hyun Choi

a, Yong-Joo Doh

b, and Hu-Jong Lee

a,*

a Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea

b Department of Display and Semiconductor Physics, Korea University, Sejong Campus,

Jochiwon 339-700, Korea



Phone: +82-54-279-2072, Fax: +82-54-279-5564

[keywords] Graphene, Josephson junction, macroscopic quantum tunneling, energy level quantization,

electrostatic gate, qubit.

Graphene-based Josephson junctions (GJJ’s), consisting of monolayer graphene in contact with two

superconducting electrodes, provide a unique platform to investigate superconducting proximity effect

with in-situ gate-tunable Josephson coupling strength. While the phase-coherent behaviors of a GJJ

under an external magnetic field and microwave irradiation have been observed previously [1],

behavior of the quantum states of the system is far less investigated. We present observation of the

three different escaping regimes for a phase particle from a washboard potential of the GJJ [2]; i.e.,

regimes of macroscopic quantum tunneling (MQT), thermal activation (TA), and phase diffusion

(PD). Most interestingly, the crossover temperature (T*MQT, T

*TA) between the adjacent quantum

regimes can be controlled by the gate voltage, implying that discrete energy levels of a phase particle

is also gate-tunable. Moreover, The energy level quantization (ELQ) in the washboard potential is

directly confirmed by the multiphoton absorbed MQT under microwave irradiation.. A new class of

hybrid quantum devices such as a gate-tunable phase qubit is potentially realized by utilizing the MQT

and ELQ behavior of the GJJs.

References

[1] H. B. Heersche et al., Nature 446, 56 (2007); D. Jeong et al., Phys. Rev. B 83, 094503 (2011). [2] G.-H. Lee et al., Phys. Rev. Lett. 107, 146605 (2011).



42

Phenomenological Models of Layered Superconductors

Richard A. Klemma

a Department of Physics, University of Central Florida, Orlando, FL 32816, USA


Phone: +1-407-822-1160, Fax: +1-407-823-5512

[keywords] Intrinsic Josephson Junctions, London model, Ginzburg-Landau model, Lawrence-

Doniach model, pancake vortices, dimensional cross-over effects

In principle, layered superconductors consist of stacks of coupled superconducting layers [1]. Many

layered superconductors exhibit strong interlayer electronic coupling, and are hence not very

anisotropic in their normal state and superconducting state properties. In these materials, simple

phenomenological models such as the anisotropic London model [1,2] and the anisotropic Ginzburg-

Landau model [1,3,4] can describe most of their superconducting properties. However, the more

interesting materials exhibit interlayer coupling that is so weak that the materials that the normal state

single electron tunneling normal to the layers is almost non-existent, and the primary coupling in the

superconducting state is by Josephson tunneling [1,5]. In these cases, the materials behave as stacks of

Josephson junctions, and are best described phenomenologically by the Lawrence-Doniach model [5].

For magnetic fields near to parallel to the layers, this model leads to dimensional cross-over effects in

the upper and lower critical fields [1,6,7], with a lock-in transition of the magnetic vortices when the

external magnetic field is nearly parallel to the layers [1,7], as well as in the fluctuation behavior

above the superconducting transition temperature Tc [1]. In such cases, Josephson plasmas,

macroscopic quantum tunneling and coherent electromagnetic emission can occur [1]. For very weak

Josephson coupling with the magnetic field not nearly parallel to the layers, the vortices form stacks of

pancakes [1,8].

References

[1] R. A. Klemm, Layered Superconductors, Volume 1 (Oxford University Press, Oxford, UK and

New York, NY, 2012) ISBN 978-0-19-959331-6,International Series of Monographs on Physics 153.

[2] V. G. Kogan, Phys. Rev. B 24, 1572 (1981).

[3] R. A. Klemm and J. R. Clem, Phys. Rev. B 21, 1868 (1980).

[4] R. A. Klemm, Phys. Rev. B 47, 14630(R); ibid. 49, 752 (1994).

[5] W. E. Lawrence and S. Doniach, in E. Kanda (ed.), Proceedings of the Twelfth International

Conference on Low Temperature Physics (Academic, Kyoto, Japan, 1972), p. 361.

[6] R. A. Klemm, A. Luther, and M. R. Beasley, Phys. Rev. B 12, 877 (1975).

[7] L. N. Bulaevskii, M. Ledvij, and V. G. Kogan, Phys. Rev. B 46, 366 (1992); ibid. 46, 11807

(1992).

[8] J. R. Clem, Phys. Rev. B 43, 7837 (1991).



43

Intrinsic flux of correlated electrons and holes for deepening in

Intrinsic Josephson effects

M. Saglama*

and Z. Saglamb

a Department of Physics, Ankara University, 06100 Tandogan, Ankara, Turkey

b Department of Physics, Faculty of Science, Aksaray University,68100, Aksaray,Turkey



Phone: +90-312-2126720, Fax: +90-312-2232395

[keywords] Intrinsic flux of electron, Intrinsic Josephson effect, Flux quantization, Quantum

entanglement.

One of the most important properties of the Josephson structures is the total quantum flux which

can be related to the phase difference across the junction. For example the sign of the phase difference

controls the direction of the Josephson current while the magnitude of the phase difference effect the

critical current itself [1]. In all these calculations the starting point is the canonical momentum which

is given by [2]: )2/()(][)()( 0 eJArevmrpxrJ zzzzc

. So far in literature to

calculate the total quantum flux in Josephson structures only the flux of the external magnetic field

(and hence the external vector potential) has been considered but the intrinsic quantum flux of

electrons and holes have not been taken into account. We have recently calculated the intrinsic

quantized magnetic flux of electrons and holes [2-4]. We showed that depending on the spin

orientations, the spin contribution to the quantized intrinsic flux of a correlated electron is equal to

)2/( 0

*

int g . Here *g is the effective Landé-g factor and

215

0 .100678.2)2( mTxeh

is the unit of flux (fluxoid). In the present study we calculate the above mentioned phase differences

across the junction considering the intrinsic quantum flux of electrons and holes. For electrons the

additional flux contribution will be: )2/( 0

*

int eg and for holes, the related contribution will

be: )2/( 0

*

int hg .We show that, for both charge carriers, the effective Landé-g factors (*

eg ,

*

hg ) take only even integer values such as ...6,4,2,0 . The present calculations can be easily extended

to the intrinsic Josephson junctions as well.

References

[1] B. D. Josephson, Phys. Lett. 1, 251(1962).

[2] M.Saglam and G. Sahin, Int. J. Mod. Phys. B.23 (24) 4977 (2009).

[3] M.Saglam and B.Boyacioglu , Int. J. of Mod. Phys. B, 16, 607 (2002).

[4] M.Saglam, Physica E,17, 345 (2003).

[5] K. K. Wan and M.Saglam, Int. J. of Theor. Phys. 45(6), 1171 (2006).

mailto:[email protected]



44

Get over Terrible Disasters from Earthquake and Tsunami

Tsutomu Yamashita

Tohoku University Japan


[keywords] SQUID, high frequency magnetic flux, geomagnetism observation.

At March 2011, quite strong Earthquake attacked the wide area of north Japan and heavy Tsunami

followed immediately. About 20 thousand people were died and disappeared. Myself and wife were

fortunately escaped from Tsunami and survived. But my lovely house was washed away and

disappeared completely.

Many people remember that in Turkey at August 1999, strong earthquake attacked the North West

area. Number of died and missed people were about 17 thousand, comparable to that of Japan. Such

huge disasters should be minimized by earthquake prediction.

One effective earthquake prediction method is believed to be geomagnetism observation. The most

sensitive device to measure magnetic flux is now SQUID. The method to detect dc or high frequency

magnetic flux is expected to be one of a best candidate for earthquake prediction



45

Effect of thermal inhomogeneity of intrinsic Josephson junction

stack for excitation of synchronized terahertz Josephson plasma

oscillations

I. Kakeya*, Y. Omukai, N. Hirayama, S. Mizuta, and M. Suzuki

Department of Electronic Science and Engineering, Kyoto University, Kyoto, Japan



Phone: +81-75-3832265, Fax: +81-75-3832270


Radiations of monochromatic and continuous electromagnetic waves with frequencies ranged

between 0.3 and 0.9 THz and powers up to 5 W from rectangular mesa structures of Bi2212 intrinsic

Josephson junction (IJJ) have been reported [1]. The radiation is described by the synchronization of

standing waves (cavity modes) of thousands of stacked IJJs although the lengths of the IJJs are not

uniform because of the trapezoidal cross section of the mesa [2]. So far, it has not been clarified yet

the property of a sample which divides into emitting and non-emitting. This is because of lack of

systematic experimental results with carefully controlled junction parameters. Therefore, the central

issue of this study is how to induce the synchronized Josephson plasma oscillations by varying a

junction parameter which changes thermal distribution inside the mesa: thickness of the electrode.

We prepared several mesa structures with the same geometry of 80 x 400 x1.0 m3 but different

thicknesses of Ag electrodes on Bi2212 single crystals. The electrode thicknesses are 30, 70, 400 nm

for types A, B, and C, respectively. THz emission was observed in types A and B, whereas neither

response of the bolometer nor voltage jumps in IV characteristics were found in type C. Since the THz

emission is found at the resistive quasiparticle branch of the IV characteristics, temperature of the

mesa is raised by the injected bias current. The temperature rise is more significant in a mesa with

thinner electrode because the electrode is a major heat leak path. As a matter of fact, a voltage

overshoot just above the critical current as a result of suppression of superconducting gap and slow

thermal relaxation of the mesa is more pronounced in mesas with thinner electrodes showing the THz

emission. Therefore, the local temperature rise is considered to be the origin of the synchronization of

phase kink for the THz emission.

*This work is supported by KAKENHI (Grait-in-Aid for Scientific Research, Japan Society for the

Promotion of Science) project number 23681030. The authors acknowledge to T. Yamamoto and K.

Kadowaki for supplying high-quality single crystals.

References

[1] L. Ozyuzer et al., Science 318 1291 (2007). H. Minami et al., App. Phys. Lett., 95 232511 (2009).

[2] S. Lin and X. Hu, Phys. Rev. Lett., 100, 247006 (2008), A. Koshelev and L. Bulaevskii Phys. Rev.

B 77 140530 (2008), T. Koyama et al., Phys. Rev. B 79 104522 (2009).



46

Coherent generation of phonon-polaritons in Bi-2212 intrinsic

Josephson junctions

Sven-Olof Katterwe, Holger Motzkau, Andreas Rydh and Vladimir Krasnov

Department of Physics, Stockholm University, AlbaNova University Center, SE-10691, Stockholm,

Sweden.

[email protected]

Light does not propagate through metals because of the negative dielectric constant

electromagnetic (EM) interaction with charged particles, which is strongest in polar materials, such as

ionic insulators and ferroelectrics. Resonances between light and EM-active collective modes may

lead to formation of polaritons, half light - half matter particles, with zero group velocity. Here we

study propagation of transverse EM waves in single crystals of Bi2Sr2CaCu2O8+x (Bi-2212) high-Tc

superconductor. We employ the intrinsic Josephson effect for in situ generation and detection of EM

waves. It is observed that EM waves do not only propagate along the ab-planes but also form

polaritons with several c-axis infrared and Raman active transverse optical phonons [1]. This shows

the presence of unscreened polar response in cuprates, even in the metallic and superconducting state.

Our observation indicates that Bi-2212 is not just an anisotropic metal, but rather has the unusual

metamaterial-type structure, in which 2D metallic CuO bilayers are sandwiched between ionic BiO

planes. The presence of unscreened polar response in BiO may lead to unusually strong electron-

phonon interaction.

[1] S.O.Katterwe, H.Motzkau, A.Rydh and V.M. Krasnov, Phys. Rev. B 83, 100510 (R) (2011)

mailto:[email protected]



47

Increasing THz Radiation Power and Monotonicity Using

Optically Induced Photonic Crystal in Layered Superconductors

Alireza Kokabia,*

, H. Kamrania, M. Fardmanesh

a

a Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran



Phone: +98-21-66165989, Fax: +98-21-66165989


The possibility of enhancing the radiation power and monotonicity by optically induced photonic

crystal in the superconducting cavity is proposed and investigated. In such a structure, by periodically

irradiating the stacked Josephson junctions and consequently partially suppression of the

superconductivity in the irradiated positions due to depairing, a periodic optical configuration is

formed. This leads to photonic band gap opening in the range of the terahertz radiation emitted from

the layered superconductor. We show that such a photonic band gap significantly enhances the

impedance matching at the boundary of the cavity and the waveguide. Since the weak optical coupling

of the outer and inner space of layered superconductor samples is a serious reason of reducing radiated

power especially in the experiments, the proposed configuration is capable of extremely enhancement

in the emitted power along with attenuation of the undesired harmonics. The effect of imposing this

periodic illumination on the boundary impedance matching, power enhancing and higher harmonic

suppression is also presented in this work.

References


[2] Y. Nonomura, “Stationary phase-kink states and dynamical phase transitions controlled by surface

impedance in terahertz wave emission from intrinsic Josephson junctions,” Phys. Rev. B, vol.

80, pp. 140506(R)-1-4, Oct. 2009.

[3] A. E. Koshelev and L. N. Bulaevskii, "Resonant electromagnetic emission from intrinsic

Josephson-junction stacks with laterally modulated Josephson critical current," Phys. Rev. B, vol. 77,

pp. 014530-1-15, Jan. 2008.



48

Superconducting Properties of K-doped Fullerene Nanowhiskers

Y. Takano1,2)

, H. Takeya1,2)

, T. Ozaki1,2)

, H. Okazaki1,2)

, T. Yamaguchi1,2)

, R. Kato1)

, T.

Wakahara1)

, and K. Miyazawa1)

1)

National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047, Japan 2)

JST, Advanced Low Carbon Technology R&D Program (ALCA), Chiyoda-ku, Tokyo 102-0075,

Japan



Phone: +81-29-859-2842, Fax: +81-29-859-2601

[keywords] Superconductivity, Fullerene, Nanowhiskers.

Superconductivity of alkali doped fullerene was found in 1991. K3C60, shows superconductiviting

transition at 19 K. The large superconducting volume faction was difficult to obtain by the simple

solid reaction method. In addition, the synthesized bulk superconductors of K3C60 were usually

obtained in powders or small particles, whose forms were not suitable for the application such as

superconducting wires and devices. These facts were the problems for the application of K3C60

superconductors.

Flexible fullerene nanowhiskers (C60NWs) have been developed by Miyazawa et al. [1] If such a

form of C60NW turns out to be a superconductor, the nanowhisker will be a promising material for the

superconductive wires, sheets and devices. We assumed that C60NWs would behave the same as C60

for the K intercalation, then we tried to dope K into C60NW in the nominal composition range of x=0-

6 vs. C60 unit. K was easily doped into C60NWs by heating at 200 degree C for 24 h and they showed

superconductivity at 17 K with superconducting volume fractions as large as 80 %. On the other hand,

the transition of K3.3C60 was observed at 19 K and the fraction was less than 1 %. We will present

the detailed information of C60NW superconductor.

References

[1] K. Miyazawa, Y. Kuwasaki, A. Obayashi, and M. Kuwabara, J. Mater. Res., 17, 83 (2002).



49

Carrier Doping of Intrinsic Josephson Junctions by c-axis

Current Injection

Paul Müller*

Department of Physics and Interdisciplinary Center for Molecular Materials (ICMM)

Universität Erlangen-Nürnberg, Germany



Phone: +49-9131-8527272, Fax: +49-9131-15249

[keywords] Intrinsic Josephson junctions, carrier doping, current injection, pnictides.

All high-Tc cuprates are stacking sequences of CuO2 layers and charge reservoir layers consisting of

metal oxides. Upon doping the CuO2 layers, antiferromagnetic order is destroyed and metallic

conductivity is established. Usually doping is achieved by a non-stoichiometric composition of the

charge reservoir layer. However, we already have shown that we can change the carrier concentration

of Bi2Sr2CaCu2O8+ single crystals by current injection along the c-axis [1]. Critical temperature, c-

axis resistivity and critical current of intrinsic Josephson junctions can be tuned in a large range from

underdoping to extreme overdoping. This effect is persistent up to annealing temperatures of

approximately 270 K. Using current injection at higher bias, we were able to reduce the carrier

concentration again. We investigated in detail the superconducting properties by performing

macroscopic quantum tunneling experiments of intrinsic Josephson junctions. The experiments have

been carried out repeatedly on samples, whose properties were changed only by current injection. An

exponential increase of the critical current density with hole concentration was observed. At the same

time, the capacitance of intrinsic Josephson junctions increased significantly. Finally, only by current

injection, we were able to convert into the superconducting state a non-superconducting, oxygen

depleted sample. Finally, we compare our cuprate results with recent data on (1111) pnictides.

References

[1] Y. Koval, X.Y. Jin, C. Bergmann, Y. Simsek, L. Özyüzer, P. Müller, H. B. Wang, G. Behr, B.

Büchner, Appl. Phys. Lett. 96. 082507 (2010).).



50

Phase Diffusion in Intrinsic Josephson Junctions

P. A. Warburtonab* , J. C. Fenton

a, S. Saleem

a,

T. A. Woottonb, L. D. Ward

b and S. M. I. Rizvi

b

a London Centre for Nanotechnology, University College London, London, UK

b Department of Electronic and Electrical Engineering, University College London, London, UK



Phone: +44 20 7679 3971

[keywords] Intrinsic Josephson junctions, Josephson phase diffusion.

When an overdamped (non-hysteretic) Josephson junction is biased at a current i below its

critical current, the Josephson phase advances in a diffusive fashion, leading to a small but

measureable thermally-activated voltage vpd with ∂2i/∂vpd

2 < 0. Phase diffusion can also be observed in

hysteretic Josephson junctions (i.e. when the low-frequency dynamics are underdamped) provided that

the viscosity is frequency-dependent and the damping is high at the Josephson plasma frequency.

Furthermore, Koval et al. [1] have shown that Josephson junctions irradiated at microwave

frequencies display a strong enhancement of the phase diffusion voltage, which at high irradiation

intensities can lead to ∂2i/∂vpd

2 > 0.

While the experimental situation is well understood in the case of single Josephson junctions,

it is currently less well characterized in the case of arrays of junctions, including intrinsic junctions.

Classical phase diffusion with ∂2i/∂vpd

2 < 0 has been observed by both the London and Erlangen

groups [2, 3]. It was further shown [4] that the damping depends upon the number of junctions which

are in the voltage state. In the presence of microwave radiation, Koval et al. [1] showed that the

dissipative branch with ∂2i/∂vpd

2 > 0 which had formerly been attributed to microwave-induced vortex-

flow, was probably due to microwave-enhanced phase diffusion.

In this paper we will survey the phase diffusion phenomena which can be observed in intrinsic

Josephson junctions. We will additionally show that, by integrating passive components in close

proximity to the junction stack, it is possible to control the dissipation of the stack at the plasma

frequency. This has enabled us to observe a new phase-diffusion phenomenon: namely a dissipative

branch with ∂2i/∂vpd

2 > 0 in the absence of external microwave radiation. We propose that this branch

arises from the mutual coupling of thermally-activated phase-slips between the junctions in the stack –

or, in other words, self-induced “microwave”-enhancement of the phase diffusion voltage.

This research is supported by EPSRC.

References

[1] Y. Koval, M. V. Fistul and A. V. Ustinov Phys. Rev. Lett. 93 087004 (2004)

[2] P. A. Warburton et al. Phys. Rev. B 67 184513 (2003)

[3] A. Franz et al. Phys. Rev. B 69 014506 (2004)

[4] P. A. Warburton et al. Phys. Rev. Lett. 103 217002 (2009)



51

Comparison of phase slippage processes in Josephson junctions

and in charge density wave stacked junctions

Yu.I. Latyshev

Kotelnikov Institute of Radio-Engineering and Electronics, RAS, Mokhovaya 11-7, 125009

Moscow, Russia



Phone: +7(495)629 3678, Fax: +7(495) 629 3656

[keywords] Josephson Junctions, charge density wave, pase slippage.

We discuss time – space symmetry in the processes of phase slippage in Josephson junctions and

charge density wave (CDW) stacked junctions. In Josephson junctions phase slip by 2π occurs

periodically in time with a period T above critical current with a frequency obeys Josephson relation

= 1/T= 2eV/h, where V is the voltage on the junction. In CDW stacks at voltage on the stack above

threshold value the CDW dislocation appears in the weakest junction of the stack. This phase

dislocation corresponds to the local phase slippage by 2π. With voltage increase a new dislocations

appear forming periodic array of dislocations with a period L. The inverse spacing 1/L follows the

analog of Josephson equation vF/L = 2eV/h.

* The work has been supported by RFBR grant No 11-02-01379-a and RAS programs.



52

Josephson Effects in Topological Insulator Nanoribbons

Yong-Joo Doh

Department of Display and Semiconductor Physics, Korea University Sejong Campus,

Chungnam 339-700, Korea


Phone: +82-41-860-1376, Fax: +82-41-865-0939

[keywords] Josephson Junctions, topological insulator, nanoribbon, Bi2Se3

Topological insulators are exotic materials with bulk band gap and metallic edge states which are

protected on their own boundary topologically. Here, we report on the fabrication and measurement

results of the superconducting proximity junctions of topological insulator nanoribbons of Bi2Se3.

Single-crystalline Bi2Se3 nanoribbons are synthesized using the vapor-liquid-solid method, while the

superconducting Al electrodes are formed on top of the nanowire. When a magnetic field (H) is

applied along the nanoribbon axis, the magneto-resistance data exhibit quasi-periodic oscillations with

a periodicity of H* ~ 0.5 T. Increasing temperature or bias suppresses the oscillations to be vanished,

which infers that the oscillations are due to a phase coherent electrical transport. In the

superconducting state, the supercurrent branch with a critical current of Ic ~ 80 nA is clearly observed

in the current-voltage curve. Irradiated with the microwave field, the Bi2Se3 nanoribbon Josephson

junction exhibits quantized voltage steps satisfying the ac Josephson relation.

*This research is supported by Basic Science Research Program through the National Research

Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (grant

number 2011-0013900).



53

Revisit to Terahertz Wave Emission with Motions of Josephson

Vortices

Hideki Matsumoto a,b*

, T. Koyama a

, M. Machidac and Y. Ota

d

a Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

b Department of Physics, , Graduate School of Science, Tohoku University, Sendai 980-8578, Japan

c CCSE, Japan Atomic Energy Agency, Kashiwa, Ibaraki 277-8587, Japan

d Riken Advanced Science Institute , Wako,Saitama 351-0198, Japan



Phone: +81-(0)224-34-4580, Fax: +81-(0)224-34-4580


After the observation of a strong terahertz wave emission from Bi2212 mesa[1], much studies have

been made for cases without an applied magnetic field. Magnetic field-effects have been investigated

in ref. [2] with the conclusion that the emitted power is generally reduced in the fundamental mode.

Motivated by the recent numerical results of power enhancement from interface with surrounding

fields (which will be presented also in this symposium), terahertz wave emission with motions of

Josephson vortices is reinvestigated by use of recently developed multi-scaled simulation method[3].

Results show that there appears a strong wave emission around the n=2 cavity mode (one wavelength

mode), when motions of vortices and cavity modes are resonate. Resonant condition will be discussed.

*This research is partially supported by JST-CREST and the Grant-in-Aid, Ministry of Education,

Japan

References [1] L. Ozyuzer et al, Science 318, 1291 (2007).

[2] Y. Nonomura, Physica C 470, S824 (2010).

[3] T. Koyama, H. Matsumoto, Y. Ota and M.Machida, Supercond. Sci. Technol. 24, 05007 (2011).



54

Quantum Phases in Intrinsic Josephson Junctions:

Quantum Magnetism Analogy

M. Machidaa , K. Kobayashi

a, Y.Ohta

b, and T.Koyama

c

a CCSE, Japan Atomic Energy Agency, Kashiwa, Ibaraki 277-8587, Japan

b Riken Advanced Science Institute , Wako,Saitama 351-0198, Japan

c Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan



Phone: +81-(0)4-7135-2349, Fax: +81-(0)4-7135-2382

[keywords] Intrinsic Josephson Junctions, Quantum Phases, Magnetism.

Since the discovery of intrinsic Josephson effects in Bi-2212 single crystal, a tremendous number of

theoretical and experimental studies have been made on the coupling between stacked Josephson

junctions. Consequently, we believe that two types of novel coupling, which are widely called

“capacitive coupling”[1,2] and “inductive coupling”, have been established.

In this talk, we concentrate on an intrinsic Josephson junction with small ab-plane square whose

one-side length is submicron scale. In such a slim intrinsic Josephson junction, we expect that

quantum features become predominant and unexplored quantum phases emerge[3]. Starting with the

established Hamiltonian considering both couplings or dropping each of them owing to small-size

confinement, we map the Hamiltonian onto quantum-spin interacting models [4] and draw new

insights through quantum magnetism analogy. A highlight in this talk is that we can make a

topologically protected state, which is called “Haldane gap phase” well-known in quantum magnetism

by using intrinsic Josephson junctions. Various rich features due to the Haldane gap are addressed, and

possibility of quantum computation using the topological state is discussed.

*This research is partially supported by JST-CREST and the Grant-in-Aid, Ministry of Education,

Japan

References [1] T. Koyama and M.Tachiki, Phys. Rev. B 54, 16 183 (1996). [2] M.Machida, T.Koyama, and M.Tachiki, Phys. Rev. Lett. 83, 4618 (1999). [3] M. Machida, and T. Koyama, Superconductor Science and Technology 20, S23 (2007).

[4] K. Kobayashi et al. (in preparation).



55

Current Voltage Characteristics and Resonance Features of

Coupled Josephson Junctions

Yury Shukrinov a,b*

, Mahmoud Gaafar a,c

, Ilhom Rahmonov a,b

, Kirill Kulikov a

,

Mohammad Hamdipour a,d

, Mohammad R. Kolahchi d

, Andre Botha e, Minoru Suzuki

f,

Eman Hamza g

, Khaled Hegab g

, Abdelhamid Galal g

, Hazem Abdelhafiz h

,

Karim Elgammal h

, Ahmed Foda h

.

a Joint Institute for Nuclear Research, BLTP, Dubna, Russia

b Physical Technical Institute, Dushanbe, Tajikistan

c Department of Physics, Faculty of Science, Menoufiya University, Egypt

d Institute for Advanced Studies in Basic Sciences, P.O.Box 45195-1159, Zanjan, Iran

e Department of Physics, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa f Photonics and Electronics Science and Engineering Center and Department of Electronic Science

and Engineering, Kyoto University, Kyoto 615-8510, Japan g Cairo University, Cairo, Egypt

h Nile University, Smart Village, Cairo, Egypt



Phone: +7-49621-63844, Fax: +81-+7-49621-65084

[keywords] intrinsic Josephson junctions, phase dynamics, CCJJ model, CCJJ+DC model, current

voltage characteristics, breakpoint, longitudinal plasma wave, shunting, chaos.

We present the results on phase dynamics of the intrinsic Josephson junctions (IJJ) in high

temperature superconductors in the framework of various theoretical models. The current voltage

characteristics (CVC) and time dynamics of the electric charge in the superconducting layers are

numerically calculated. We demonstrate the influence of microwave irradiation on the CVC and

temporal oscillations of the electric charge [3]. Charging of layers and irradiation lead to different

features in CVC, in particular, to a “bump” in the outermost branch. The CVC with such bumps were

observed experimentally [4]. The results concerning the transformation of the longitudinal plasma

wave into the charge density wave are presented. We show effect of the LCR shunting on the

parametric resonance in coupled Josephson junctions and demonstrate other resonances realized in this

system. The CVC of IJJ in different models are compared and we demonstrate the role of the diffusion

current between the superconducting layers in different phenomena. Chaotic features of coupled JJ are

discussed. We present results on simulation of Lyapunov exponents and demonstrate the hyperchaotic

behavior in the parametric resonance region.

References

[1] M. Machida, T. Koyama, A. Tanaka and M. Tachiki, Physica 330, 85 (2000).

[2] Yu. M. Shukrinov, F. Mahfouzi, P. Seidel. Physica C 449, 62 (2006).

[3] Yu. M. Shukrinov and M. A. Gaafar,. Phys.Rev.B, 84, 094514 (2011)

[4] F. Turkoglu, H. Koseoglu, Y. Demirhan, L. Ozyuzer, S. Preu, S.

Malzer, Y. Simsek, P. Muller, T. Yamamoto and K. Kadowaki, unpublished.



56

Phase diagram of frustrated proximity sandwich composed of s

and s± superconductors

A. E. Koshelev* and V. Stanev

Materials Science Division, Argonne National Laboratory, Illinois, USA



Phone: +1-630-2529592, Fax: +1-630-2527777

[keywords] iron pnictides, proximity.

The leading candidate for superconducting state in the iron-based superconductors is the s± state in

which the order parameter has different signs in the electron and hole bands. We study proximity

effects between s and s± superconductors. Frustration, caused by interaction of the s-wave gap

parameter with the opposite-sign gaps of s± superconductor, leads to several anomalous features. We

study this system using a simple microscopic model assuming dirty limit in all bands, which allows us

to describe the system in terms of minimum number of the most relevant parameters. In the case of

strong frustration, a nontrivial time-reversal-symmetry breaking (TRSB) state, with nonzero phase

angles between all gap parameters, is possible. In the weak coupling limit this state presents a

Josephson junction with non-zero phase difference in ground state (“-junction”). We find parameter

range where such state is realized. In a more typical state, the s-wave order parameter is aligned with

one of the s± gaps. In this case the other (anti-aligned) gaps induce negative features in the s-wave

density of states, which can serve as fingerprints of s± state [1]. Another consequence of the frustration

is an extended region in the parameter space in which s-wave superconductivity is suppressed despite

being in contact with nominally stronger superconductor (negative proximity effect). It occurs that the

negative-proximity range not only covers the TRSB state, but also considerably extends into the

aligned states. These anomalous features provide a route to establishing the possible s± state in the

iron-based superconductors.

*This work was supported by UChicago Argonne, LLC, operator of Argonne National Laboratory,

a US DOE laboratory, operated under contract No. DE-AC02-06CH11357, and by the Center for

Emergent Superconductivity, an EFRC funded by the U.S. DOE under Award Number DE-

AC0298CH1088.

References

[1] A.E. Koshelev and V. Stanev, Europhys. Lett. 96, 27014 (2011).



57

Synchronization in mesa array by radiation field

inside base crystal

A. E. Koshelev

Materials Science Division, Argonne National Laboratory, Illinois, USA


Phone: +1-630-2529592, Fax: +1-630-2527777

[keywords]THz radiation, Intrinsic Josephson junctions, mesa array

Stacks of intrinsic Josephson junctions in high-temperature superconductors are promising

candidates for developing of powerful terahertz sources. It was demonstrated that about 700 junctions

in a mesa fabricated on the top of Bi2Sr2CaCu2O8 single crystal can be synchronized by excitation of

the internal cavity resonance [1]. A natural route to further enhancement of the radiation power is to

use mesa arrays fabricated on the same crystal, instead of a single mesa. It was demonstrated recently

that at least three mesas in such an array can be synchronized leading to significant enhancement of

the radiation power [2]. The most probable mechanism of synchronization between the mesas in the

array is via the electromagnetic (EM) radiation leaked into the base crystal. To develop a better

understanding of this mechanism, we analyzed EM oscillations inside the base crystal generated by the

synchronized mesa array. Studying dependence of these oscillations on the array parameters allows us

to find best conditions for the most efficient synchronization.

*This work was supported by UChicago Argonne, LLC, operator of Argonne National Laboratory,

a US DOE laboratory, operated under contract No. DE-AC02-06CH11357.

References

[1] L. Ozyuzer, A. E. Koshelev, C. Kurter, N. Gopalsami, Q. Li, M. Tachiki, K. Kadowaki, T.

Yamamoto, H. Minami, H. Yamaguchi, T. Tachiki, K. E. Gray, W.-K. Kwok, U. Welp,

Science 318, 1291 (2007).

[2] T. M. Benseman, K. E. Gray, A. E. Koshelev, W.-K. Kwok, U. Welp, K. Kadowaki, T.

Yamamoto, preprint.



58

TALKS



59

Detection of Terahertz Waves from

High Temperature Superconducting Bi2Sr2CaCu2O8+δ

L. Ozyuzera,

*, Y. Demirhana, F. Turkoglu

a, H. Saglam

a, H. Koseoglu

a, H. Alaboz

a,

K. Kadowakib, Y. Simsek

c, P. Müller

c

a

Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey bUniversity of Tsukuba, Tsukuba, Japan

cDepartment of Physics, University of Erlangen, Germany



Phone: +90-232-7507705


There are many potential applications of terahertz waves such as airport security, wireless

communications, cancer detection, etc. High-Tc superconductor Bi2Sr2CaCu2O8+δ (Bi2212)

single crystal has been observed as an intense, coherent, continuous electromagnetic wave

source in terahertz frequency region [1]. Bi2212 which is highly anisotropic high-Tc

superconductor is considered as a stack of intrinsic Josephson junctions (IJJs) on atomic scale

[2]. Rectangular Bi2Sr2CaCu2O8+d (Bi2212) mesa structures were fabricated on Bi2212 single

crystal superconductors using standard photolithography, e-beam lithography and Ar ion

beam etching techniques. We have performed c-axis resistance versus temperature (R-T),

current-voltage (I-V) characteristics and bolometer measurements. Furthermore, in contrast to

previous studies, the emission frequency was determined using interferometer set up instead

of FTIR. The interference patterns were detected outside the cryostat after traveling long way

through ambient space. The emission frequency calculated by Fourier transform of

interference data is consistent with Josephson frequency voltage relation.

*This research is partially supported by TUBITAK (Scientific and Technical Research

Council of Turkey) project number 110T248.

References


[2] R. Kleiner et al., Phys. Rev. Lett. 68, 2394 (1992).



60

Current induced lock-in phenomena in Y-123 and Bi-2212 IJJs

under layer parallel magnetic field

Takeshi Hatano* and Huabing Wang

National Institute for Materials Science, Tsukuba, 305-0047 Japan



Phone: +81-29-859-2844, Fax: +81-29-859-2801

[keywords] Intrinsic Josephson Junctions, Josephson vortex, lock-in phenomena.

Layered oxide high-Tc superconductors, being regarded as intrinsic Josephson junctions (IJJs), are

widely studied for novel device applications. One of the major applications is the THz oscillator in

which all the junctions in the stack are expected to work coherently. On the other hand, the IJJs are a

densely packed 3 dimensional device array whose structural perfection is guaranteed by the

translational symmetry of the single crystal. In this sense, if we could manipulate the junctions one by

one, IJJs are a promising candidate of 3dimensional ultra-high density, ultra-fast operating and ultra-

low power consumption device of the 21st century. Further, in IJJs there are Josephson and pancake

vortices which behave opposite way with mutual interactions. Those fluxons are the possible candidate

of the digital applications of IJJs.

We have observed a flash memory behavior in highly anisotropic Y-123 (~35) IJJs under the near

layer-parallel magnetic field. The basic concept for the memory operation is the current induced

transition of flux-flow state in IJJs which can be readable by the flux-flow voltage with low current

bias. By the transition, the flux-flow state can be (re)-programmed and this state “1” is proved to be

non-volatile. The flux-flow state can be erased by applying the higher current and again this state “0”

is kept even the current is turned off. All above operations can be understood by the hysteretic

transition of vortex configurations, namely, the Josephson vortices with and without pancake vortices

under near-layer-parallel magnetic field.

In order to examine IJJs for THz oscillators [1-3] in the flux flow regime, Josephson vortex state

without pancake vortices will be crucial so as to reduce the dissipation for the fluxon motions. Lock-in

phenomena and current-voltage characteristics have been studied for the IJJs with THz cavity size (80

µmX330 µmX1 µm) under the layer parallel magnetic field. The lock-in phenomena were measured

by measuring flux-flow voltage with bias current of 1-2 mA. A reversible lock-in phenomena were

observed at the temperature above 70 K, which was 10 K higher than that of ~µm-sized in-line-shaped

IJJs [4]. Current-voltage curves were measured in various magnetic fields and temperatures starting

from the lock-in state. It was found that the lock-in state is affected by the bias current similar to those

observed in Y-123 IJJs. Although the size of this mesa is too huge for the digital application, a feature

in common has been observed in highly anisotropic IJJs.

References [1] L. Ozyuzer, et al., Science 318, 1291 (2007).

[2] H. B. Wang, et al., Phys. Rev. Lett., 102 (2009) 017006.

[3] H. B. Wang, et al., Phys. Rev. Lett., 105 (2010) 057002.

[4] T. Hatano, et. Al., Jpn. J. Appl. Phys. 44 (2005) L27.



61

New Lock-in Phenomena in Intrinsic Joesphson Junctions of

Bi2Sr2CaCu2O8+δ with Hole-Array

K. Hirata, S. Ooi and T. Mochiku

National Institute for Materials Science, Tsukuba 305-0047, Japan



Phone: +81-29-859-2321, Fax: +81-29-859-2301

[keywords] Intrinsic Josephson Junctions, Josephson vortex, Josephson-vortex flow.

Josephson and pancake vortices (JVs&PVs) in intrinsic Josephson junctions of Bi2Sr2CaCu2O8+δ

(Bi-2212) single crystal with a nano-size hole-array have been studied with measuring the flow-

resistance of the vortices. The samples for the measurements were prepared by using a focused ion-

bean (FIB) milling for the hole-array with a diameter of about 200 nm and 1 m pitch, and by photo-

lithography for the electrodes. In the magnetic field perpendicular to the superconducting layers, flow

resistance of PVs measured with the in-plane current shows a matching behavior as usually observed

at the matching fields [1]. It shows a relatively sharp transition at the fractional matching fields and a

broad transition at the integer matching fields, which is related to the pinned vortex solid and the

floating vortex solid, respectively [2]. Furthermore, the sample was milled with the FIB into the in-line

shaped structure for the measurements with the c-axis current to obtain the JV flow-resistance.

Significant feature in the perpendicular field can be observed at the third matching field. The c-axis

resistance shows clear three-step transitions with decreasing temperature. These steps are considered

related to the accommodation number of PVs into the holes and to the interaction between/among the

vortices outside the holes (interstitial vortices) and the trapped vortices.

Using the same sample in the PV measurements, in the field parallel to the superconducting layers,

angular dependence of the JV flow-resistance does not show a usually-observed lock-in phenomenon

in JVs in Bi-2212 [3] and periodic oscillations [4]. Instead, there are observed several peaks in the

flow-resistance. It may suggest that JV flow is enhanced at some angles. As discussed by Koshelev

[5], distribution of PVs is strongly influenced with existence of JVs. In this case, changing the angle

from the in-plane magnetic field, PVs are introduced into the sample, and trapped PVs into holes and

the interstitial PVs will interact with JVs. This may cause the enhancement. A couple of peak can be

explained with the matching field effect of PVs to the hole-array, but the others not. Detailed

investigations are presented.

References

[1] S. Ooi, et al., Physica C 463-465, 271 (2007).

[2] C. Reichhardt, et al., Phys. Rev. B 64, 144509 (2001).

[3] G. Hechtfischer et al., Phys. Rev. B 55, 14638 (1997).

[4] S. Ooi, et al., Phys. Rev. Lett. 89, 247002 (2002).

[5] A. E. Koshelev, et al., Phys. Rev. B 74, 104509 (2006).



62

Superconductivity induced by carrier injection into non-

superconducting Bi2Sr2CaCu2O8

Y. Simseka,*

, Y. Kovala, X. Y. Jin

b, S. Probst

c, C. Steiner

a, P. Müller

a

a Department of Physic and Interdisciplinary Center for Molecular Materials (ICMM) Universität

Erlangen-Nürnberg, Germany b Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology,

Cambridge, Massachusetts, USA cPhysikalisches Institut, Karlsruhe Institute of Technology and DFG-Center for Functional

Nanostructures (CFN), Karlsruhe, Germany



Phone: +49-9131-85-27082, Fax: +49-9131-15249

[keywords] Intrinsic Josephson Junctions, carrier injection.

We have investigated the doping dependence of the superconducting properties of high-Tc

materials. Unlike doping by oxygen excess, we are able to change the carrier concentration of

Bi2Sr2CaCu2O8+δ (Bi2212) single crystals by carrier injection [1]. The electrons injected along c-axis

of Bi2212 are trapped in BiO and SrO layers which increases the hole concentration in CuO layers.

This method gives an opportunity to observe the evolution of c-axis transport properties of Bi2212

from the antiferromagnetic state to the superconducting overdoped phase on the same sample. In order

to eliminate the contact resistance, we have fabricated double cross-bar crystal stacks on fully oxygen

depleted Bi2212 single crystal which was not superconducting above 4.2 K. We have observed that by

carrier injection the conductivity can be increased until superconductivity above 4.2 K is reached.

Continuing the doping by carrier injection, optimum-doped and even overdoped states were obtained.

In the superconducting phase, the critical current density exponentially increases by doping level. At

the same time, the variation of the critical temperature with doping shows a well-known parabolic

behavior. This type of doping by carrier injection offers an unique opportunity of tuning the properties

of high-Tc electronic devices in situ only by applying a special treatment by transport current.

Reference

[1] Y. Koval, X.Y. Jin, C. Bergmann, Y. Simsek, L. Ozyuzer, P. Müller, H. B. Wang, G. Behr, B.

Büchner, Appl. Phys. Lett. 96, 082507 (2010).



63

Millimeter-Wave Emitting from Intrinsic Josephson Junctions

Fabricated with Misaligned Tl2Ba2CaCu2O8 Thin Film

P. Wanga, M. He

a,*, W. Xie

a, X. J. Zhao

a, X. Zhang

a,

L. Jia, L. Fang

a and S.L.Yan

a

a College of Information Technical Science, University of Nankai, Tianjin, 300071, China



Phone: +86-022-23508412, Fax: +86-022-23508412

[keywords] Intrinsic Josephson Junctions, millimeter wave, misaligned film.

Intrinsic Josephson junctions formed naturally in the layered high-temperature superconductors are

regarded as a potential candidate to fill the Terahertz gap of electromagnetic radiation. Scientists have

made great progress on Terahertz emission using Bi2Sr2CaCu2O8 (Bi-2212) single crystals [1], [2]. In

this paper, we present the characteristics of millimeter (mm) wave emitting from the intrinsic

Josephson junctions in misaligned Tl2Ba2CaCu2O8 (Tl-2212) thin films. The Tl-2212 superconducting

thin films were grown epitaxially on the LaAlO3 substrate by DC-magnetron sputtering and Ar post annealing.

The substrate surface was cut at a small angle α = 20 degree relative to the LaAlO3(001) plane. Thus,

the Cu-O planes of the Tl-2212 film formed an angle of α to the substrate surface. A microbridge with one

bow-tie antenna was patterned on the substrate. This structure makes it easy for heat to escape from

the stack into the substrate. As we have reported previously, the substrate can be regarded as a

dielectric resonant antenna. Also, the electromagnetic coupling between Josephson junctions could be

strengthened if all the junctions locate at the position of the maximum electric field intensity, which

also leads the substrate to a resonance mode at certain frequency [3]. We first simulated the

distribution of the electromagnetic field in the substrate as well as the farfield distribution of the

antennas. In the experiment, we measured the Current-Voltage (I-V) curves of the intrinsic Josephson

junctions irradiated by mm waves at frequencies ranging from 72 GHz to 80 GHz in a Fabry-Pérot (F-

P) resonator. By properly adjusting the parameters of the F-P resonator, the critical current under

irradiation was suppressed close to zero, which means optimum coupling is obtained between

Josephson junctions and the surrounding system. In the same time, the resonance mode is formed in

the substrate. At the optimal position we had observed the mm wave radiation from intrinsic

Josephson junctions. Even though the experiment was implemented at mm waves, this method is

promisingly applied to terahertz waves.

*This research is partially supported by the National Natural Science Foundation of China (Grant

No. 61101018, 51002081, 61171028, 61176119), the Specialized Research Fund for the Doctoral

Program of Higher Education of China (Grant No. 20110031120033), and the Fundamental Research

Funds for the Central Universities.

References


[2] H. B. Wang et al, Phys. Rev. Lett. 105 057002 (2010)

[3] F. B. Song, F. Műller, R. Behr and A. M. Klushin, Appl. Phys. Lett. 95, 172501 (2009).



64

Effect of Microwave Irradiation on Parametric Resonance in


Mahmoud Gaafar a,b*

, Yury Shukrinov a, and Ahmed Foda

c


b Department of Physics, Faculty of Science, Menoufiya University, Egypt

c

Center of Nanotechnology, Nile University, Smart Village, Cairo, Egypt



[keywords] intrinsic Josephson junctions, phase dynamics, CCJJ+DC model, current voltage

characteristics, breakpoint, longitudinal plasma wave, microwave irradiation.

We study the effect of microwave irradiation on the phase dynamics of intrinsic Josephson junctions

(IJJs) in high temperature superconductors in the framework of capacitively coupled Josephson

junction model with diffusion current (CCJJ+DC model) [1,2]. We demonstrated the effect of

microwave’s amplitude variation on the current-voltage characteristics (CVC) of this system and on

the time dependence (temporal oscillations) of the electric charge in the superconducting layers.

In left figure we demonstrate an example of the charge-time dependence at the parametric resonance

for the stack with 10 IJJ without irradiation (a,b) and under irradiation (c,d) with frequency ω=3 and

amplitude A=0.3. The simulation was done at coupling parameter α = 1 and the dissipation parameter

β= 0.2. Right figure shows charge-time dependence together with CVC under irradiation with

frequency ω=2 and amplitude A=0.5. It demonstrates bump feature on CVC as effect of charging and

irradiation.

We discuss in detailed the different features of CVC related to the charging of superconducting

layers and irradiation. We present analysis of the experimental CVC and make a comparison with the

results of our simulations.

References

[1] M. Machida, T. Koyama, A. Tanaka and M. Tachiki, Physica 330, 85 (2000).

[2] Yu. M. Shukrinov, F. Mahfouzi, P. Seidel. Physica C 449, 62 (2006).

[3] Yu. M. Shukrinov and M. A. Gaafar,. Phys.Rev.B, 84, 094514 (2011)



65

THz emission and response of intrinsic Josephson junctions

Akinobu Irie*, Dai Oikawa, Koichi Tamura, Kazuhiro Yamaki, Gin-ichiro Oya

Department of Electrical and Electronic Systems Engineering, Utsunomiya University,

Utsunomiya, Japan



Phone: +81-28-689-6096, Fax: +81-28-689-6096


Intrinsic Josephson junctions (IJJs) can use as oscillator and detector for THz electromagnetic wave.

We report on the experimental results of in situ detection of THz radiation emitted from large mesas

composed of a few hundred IJJs using small one at 4.2 K. Large and small mesas were separately

fabricated on different BSCCO single crystals using photolithography techniques and Ar ion milling.

The dimensions of the oscillator mesas are 290 µm in length L, 50, 70 and 90 µm in width W, and 150

− 600 nm in height H corresponding to 100-400 IJJs. Their current-voltage (I-V) characteristics are

characterized by large hysteresis and a negative resistance on the quasiparticle branch. On the other

hand, the lateral dimensions of small mesa used as detector are 5×5m2. The IJJ detector chip was

placed about 1 cm away from the IJJ oscillator chip and they were driven by individual bias circuits

which apply the ac bias current of 1mHz to oscillator and the dc current to detector. Such experimental

set-up can provide the high sensitive detection performance. As a results, we have successfully

observed THz emission from stacks with less than 300 IJJs. We found that the THz emission from the

stack which consists of a small number of junction as compared with previous studies also

corresponds to the in-phase cavity resonance mode.

This work was partially supported by a Grant-in-Aid for Scientific Research (B) and Grant-in-Aid for

challenging Exploratory Research of Japan Society for the Promotion of Science (JSPS).



66

Simultaneous Detection of THz Emission and Observation of

LTSLM Images

Jie Yuan

a,b,*, Mengyue Li

a,c, Jun Li

a,d, Stefan Guénon

e, Boris Gross

e, Akira Ishii

a,

Takeshi Hatanoa, Peiheng Wu

c, Dieter Koelle

e, Reinhold Kleiner

e, Huabing Wang

a,c

a

National Institute for Materials Science, Tsukuba, Japan b

Wuhan University of Science and technology, Wuhan, China cNanjing University, Nanjing, China

dHokkaido University, Hokkaido, Japan

e Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, University

of Tübingen, Tübingen, Germany


E-mail:[email protected]

Phone: 81-29-859-2849, Fax: +81-29-859-2801


Josephson junctions are attractive for the generation of high frequency electromagnetic radiation.

Recently, coherent off-chip THz radiation with an extrapolated output power of some μW was

observed [1]. It was reported that a “hot spot” would be helpful to synchronize the junctions in the

stacks [2, 3]. In fact, in the study of THz electromagnetic waves from intrinsic junction stacks, a low-

temperature scanning laser microscope (LTSLM) is applied to get the electromagnetic field

distributions in superconducting structures, and an interferometer is used to detect the emission and

get the power spectrum. It is interesting to know how the electromagnetic field distributions evolve as

the detected THz emission signal varies. To realize this idea, we developed a mini LTSLM system

with which the LTSLM image and the THz emission can be detected simultaneously. In this

presentation, we would like to report some results from this new system.

References

[1] L. Ozyuzere, et al., Science, 318 1291 (2007).

[2] H. B.Wang, et al., Phys. Rev. Lett., 102 017006(2009).

[3] H. B.Wang, et al., Phys. Rev. Lett., 105 057002(2010).



67

An Investigation of the Effect of Grain Size on Some Properties of

Intrinsic Josepson Junction

Özden Aslan Çataltepea,

* , Zeynep Güven Özdemirb and Ülker Onbaşlı

c

a Gedik University, Gedik MYO, Pendik, 34913 İstanbul,Turkey

b Yıldız Technical University, Physics Department, Faculty of Science and Arts, Davutpaşa Campus,

Esenler 34210, İstanbul, Turkey. c University of Marmara, Physics Department, Faculty of Science and Arts, Rıdvanpaşa cad.3.sok.,

85/12, 34730,Göztepe, İstanbul,



Phone: +90-216-5912199, Fax: +90-216-5952155

[keywords] Hg-based high temperature superconductors, Intrinsic Josephson Junctions, oxygen doping

procedure, plasma frequency, grain size

Superconducting properties of the high temperature superconductors, such as the plasma frequency,

the critical transition temperature etc, depend on the oxygen content of the superconducting material.

Moreover, the oxygen content is effective on the grain size of the system. In this study, Hg-based

copper oxide layered superconductors, which have the hole type superconductivity, have been

investigated with optimum and over oxygen contents. As is known that the density of hole type

carriers increase via optimally oxygen annealing. In other words, by means of the optimally oxygen

doping procedure, relatively higher values for the various critical parameters are achieved. In this

work, the grain size of the oxygen annealed samples has been investigated by Scanning Electron

Microscopy (SEM) and the magnetization data obtained Superconducting Interference Quantum

Device (SQUID) has been utilized. Based on these data, the Josephson penetration depth of the system

has been determined. Consequently, the plasma frequency of the various doping profiles has been

calculated for the high temperature superconductor investigated.

References

[1] Ü.Onbaşli, Physica C 332, 333 (2000).

[2] Z.G.Özdemir, Ö.Aslan and Ü.Onbaşlı, Journal of Phys. and Chem. of Sol. 67, 453 (2006).

[3] Z.Güven Özdemir, Ö.Aslan and Ü.Onbaşlı, Pramana-journal of physics 73/4, 755(2009)



68

Dynamics of resistively shunted Josephson junction (RSJ) under

the influence of second harmonics

Mehmet Canturka,*

, Iman N. Askerzadeb

a Department of Computer Engineering, Turgut Ozal University, Etlik, 06010, Ankara, Turkey

b Department of Computer Engineering, Ankara University, Keçiören, Ankara, Turkey



Phone: +90-312-551 54 35, Fax: +90-312-551 5019

[keywords] Josephson Junctions, unharmonic current phase relation.

The Josephson junctions based on high-Tc superconductors contain second harmonics. In this

work, the influence of unharmonic current-phase relation (CPR) on a resistively shunted junction

(RSJ) circuit model has been studied to understand the dynamics of the system that can be important

for various applications (such as secure communication). At zero unharmonic parameter value, RSJ

behavior is observed in the circuit but as unharmonic parameter value is increased, an anomaly

observed in the system. The anomaly in the system is attributed to nonzero unharmonicity parameter.

The numerical results seem to present the importance of second harmonics in the realization of RSJ

type Josephson junction circuits.

References

[1] E. Il'ichev, V. Zakosarenko, R.P.J. IJsselsteijn, V. Schultze, H.-G. Meyer, and H.E. Hoenig, IEEE

Trans. on Appl. Supercond., 9(2), 3994 (1999).

[2] M.Canturk and Iman N. Askerzade, IEEE Trans. on Appl. Supercond., 21(5), 3541, (2011)



69

Vortex dynamics in self-dual Josephson junction arrays near the

quantum critical point.

Said Sakhi

College of Arts and Sciences, American University of Sharjah,

P.O. Box 26666, Sharjah, UAE


Phone: +97165152508, Fax: +97165585066

[keywords] Josephson Junction arrays, Vortex dynamics, Hall effect.

Planar arrays of Josephson junctions (JJA) display rich quantum phenomena due to two competing

couplings: EJ the Josephson energy associated with tunneling of Cooper pairs between islands, and EC

the charging energy required to add extra charges to neutral islands. The low energy effective field

theory of this model is described within the framework of a mutual Chern-Simons Landau- Ginzburg

theory and consists of two complex fields coupled to two fluctuating gauge fields, leading to nontrivial

dynamics. The electromagnetic response functions are obtained at its quantum critical point. The

source of dissipation originates from the underlying dynamics of gapless bosonic excitations

interacting with the gauge fields representing the current of Cooper pairs and vortices. For unfrustrated

JJA systems, with lone excited charge-like modes, I find a universal conductivity which agrees with

previous findings. When both charge-like and magnetic-like gapless modes are concurrently excited I

find a new universal conductivity with a reduced value. In the presence of commensurate frustration

due to offset charges and external magnetic fields, I find a universal longitudinal resistance at the

critical point as well as a quantized Hall resistance. This is in contrast with earlier attempts that found

that magnetic frustrations, similarly charge frustrations, prevent in general the appearance of a

universal resistance at the transition since the gap remains finite up to the transition. The crucial point

here depends on the commensurability between the charge and magnetic frustration which guarantees

a vanishing background field seen by composite fields, resulting in gapless modes at the transition.

This new approach sheds a new light on the origin of the Hall effect in JJA systems. The quantization

of the Hall resistance is robust in the presence of quantum dissipation and the ensuing longitudinal

resistivity is finite.

References

[1] S. Sakhi, J. Phys. A: Math. Theor. 41, 085003 (2008).

[2] S. Sakhi, Phys. Rev. B 73, 132505 (2006)

[3] S. Sakhi, Journal of Low Temperature Physics: Volume 158, 631 (2010).



70

POSTERS



71

Simulation of I-V Characteristics of Josephson Junction Arrays

using RCLSJ Model

Jamal Akhtar Khana,b,*

, Abdullah A. Aljumaha, M. Shahabuddin

c

a College of Computer Engineering and Sciences, Salman bin Abdulaziz University, Saudi Arabia

b FTK-CIT, Jamia Millia Islamia, New Delhi India

c College of Science, King Saud University, Saudi Arabia



Phone: +966-561902189, Fax: +966-1-5486072

[keywords] Intrinsic Josephson Junctions, RCLSJ model

Intrinsic stacked Josephson junctions were modelled as a one-

dimensional array of Josephson junction connected in series as shown in

Fig.1. I-V curve of each junction is simulated on the basis of Resistively

Capacitively Inductively Shunted Junction (RCLSJ) Model. Magnetic

field effect and noise consideration have been taken into account.

Mathematically in the form of differential equation, RCLSJ model

is given as 2

0 12( )sin sin ( )

d dF H I I L

d d

where 2(1 )C L , we take L

L

R

Fig.1: Schematic of a Josephson

junction in the RCLSJ model. The

symbol represents an ideal

Josephson junction.

Where F(H) is given by F(H) = sin(k) / k where k = H / H0 and H0 = 0 / .d.L; H is external applied

field and 0 is flux quanta.

d = 2L + t, L = lateral dimension of junction, t = thickness of barrier

c = 2eIcRn /ħ , c t , = / c , c = c .Rn .C , I0 = Idc / Ic , I1 = Iac / Ic

A random variable L(τ) representing white Gaussian process is added to equation for which<L(t)L(t`)>=2(t-t`) where

noise parameter =2ekBTc/Ic is the thermal energy normalized to Josephson coupling energy [1].

0.0 0.5 1.0 1.5 2.0 2.5 3.0

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

Ic

IcR

n

Ir

noise level=0.01

H/H0

Fig. 2: Combined study of the applied magnetic field effect on

critical current (Ic), critical voltage (IcRn), and retrapping current (Ir)

at noise level=0.01. Inset shows the typical simulated I-V

characteristic of one dimensional series array.

The above differential equation has

been solved and I-V curves in different

magnetic field with different noise

levels were plotted. The junction

parameter Ic, IcRn and Ir (Inset of Fig.2)

calculated from the simulated curves

are shown in Fig. 2. It is like

Fraunhofer pattern. The simulated

curve is in good agreement with the

experimental results of measured I-V

curve of intrinsic stacked Josephson

junction in mesas of TBCCO and

BSCCO [2]. It is clear that the

hysteresis effect decreases with the

increasing magnetic field and vanishes

at critical field.

References:

[1] Ambegaokar V. and B. J. Halperin. Phys. Rev. Lett., 22, 1364-13-66 (1969).

[2] Paul Seidel et al. Czech. J. Phys. 46 1263-1264 (1996)

-3 -2 -1 0 1 2 3

-8

-6

-4

-2

0

2

4

6

8

IcR

n

Ic

Ir

Voltage

Current



72

Transformation of Longitudinal Plasma Wave to the Charge

Density Waves and Origin of the Branching in Intrinsic Josephson

Junction

Yury Shukrinova, Eman Hamza

b, Hazem Abdelhafiz

c,*, Khaled Hegab

b.


bCairo University, Cairo, Egypt

c Nile University, Smart Village, Cairo, Egypt

Corresponding author

E-mail address:[email protected]

Phone:+201145854525

[keywords] intrinsic Josephson junctions, CCJJ+DC model, breakpoint, longitudinal plasma wave.

Intrinsic Josephson junction (IJJ) have been the focus of many work in the resent years due to the

increasing number of applications, particularly, in high frequency devices such as THz oscillators and

mixers [1]. Recent work has shown that the coupling between junctions leads to parametric resonance

which manifest itself as a breakpoint region in current voltage characteristics [2]. The parametric

resonance is accompanied by creation of the longitudinal plasma wave (LPW) along the stack. It has

been suggested that the breakpoint phenomenon might affect the coherent radiation from the stack of

the IJJ in BSCCO.

In our presentation we discuss the longitudinal plasma wave transformation to the charge density

wave (CDW) in the parametric resonance region. We numerically calculate the charge oscillation on a

stack of IJJ in the framework of capacitively coupled Josephson junctions model with diffusion current

[3,4]. We investigate the electric charge oscillations in the stacks both with even and odd number of

junctions. An interesting behavior is observed in the end part of the breakpoint region at a transition

from the outermost branch to some other branch of CVC. A new feature appears around this point: the

chaotic behavior is changed by regular oscillations on all layers. A charge on the different layers

oscillates with an amplitude smaller than in LPW around definite charge values forming a standing

CDW.

According to Ref. [5] the reason for the multiple branching in the intrinsic Josephson junction is due

to the “freezing” of the collective LPW mode into the static CDW. We analyze different types of

transitions from the outermost branch and between other branches to study the freezing of LPW to

CDW in the stacks with different number of IJJ in order to clear the origin of branching in IJJ.

References


[2] A. Irie, Yu. M. Shukrinov, and G. Oya. Appl. Phys. Lett. 93, 152510 (2008)

[3] M. Machida, T. Koyama, A. Tanaka and M. Tachiki. Physica C330, 85 (2000)

[4] Yu. M. Shukrinov, F. Mahfouzi, P. Seidel. Physica C449, 62 (2006).

[5] M. Machida, T. Koyama, M. Tachiki. Physica C 300, 55–60 (1998) .



73

Hot Spots and THz waves in single crystal Bi2Sr2CaCu2O8

structures

B. Grossa,*, S. Guénon

a, M. Grünzweig

a, J. Yuan

b, M. Li

c, A. Iishi

b, T. Hatano

b, D.

Koellea, H.B. Wang

b and R. Kleiner

a

a Physikalisches Institut II and Center for Collective Quantum Phenomena in LISA

+, University of

Tübingen, Tübingen, Germany b

National Institute for Materials Science, Tsukuba, Japan c Nanjing University, Nanjing, China


E-mail address: : [email protected]

Phone: +49-7071-2978616, Fax: +49-7071-295406


We investigate heat distribution and electromagnetic standing wave formation in BSCCO mesas

and related structures, as well as THz electromagnetic wave generation, using a combination of

transport measurements, direct electromagnetic wave detection and low temperature scanning laser

microscopy [1,2,3]. Data on the formation of a hot spot in an overlap structure will be presented and

analyzed. Using focused ion beam milling this structure was cut into two smaller structures. The

resulting changes in its electro-thermal behavior, models to describe the relevant physics and

simulations are discussed. Furthermore, data on electromagnetic wave formation in the sample before

and after cutting are discussed.

References

[1] Wang, H.B. et al. “Hot spots and waves in Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks -a

study by Low Temperature Scanning Laser Microscopy”, PRL, Vol. 102, pp. 017006, 2009

[2] Wang, H.B. et al. “Coherent THz emission of intrinsic Josephson junction stacks in the hot spot

regime”, PRL, Vol. 105, pp. 057002, 2010

[3] Guénon, S. et al. “Interaction of hot spots and THz waves in Bi2Sr2CaCu2O8 intrinsic Josephson

junction stacks of various geometry”, PRB, Vol. 82, pp. 214506, 2010



74

Unconventional Gap Structures of Bi2Sr2CaCu2O8+δ Revealed

from Intrinsic Josephson Junction Tunneling Spectroscopy

Minoru Suzuki a,b,*

, Takashi Hamatani a

, Kenkichi Anagawa a

,

and Takao Watanabe c

a Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan

b Photonics and Electronics Science and Engineering Center, Kyoto University, Nishikyo-ku, Kyoto

615-8510, Japan c Department of Advanced Physics, Hirosaki University, Hirosaki, Aomori 036-8561, Japan



Phone: +81-75-383-2263, Fax: +81-75-383-2270

[keywords] Intrinsic Josephson Junctions, interlayer tunneling spectroscopy, superconducting gap,

pseudogap, Fermi arcs, Josephson critical current density, doping dependence.

Intrinsic Josephson junctions [1] provide a very important probe into the bulk properties of layer-

structured high-Tc superconductors, in particular, into the superconducting properties of

Bi2Sr2CaCu2O8+δ (Bi2212). From intrinsic Josephson junction tunneling spectroscopy, it is found that

the superconducting gap structure evolves magnificently as doping level increases while the

pseudogap develops overwhelmingly as doping decreases. Accompanying these changes, it is also

found that the Josephson critical current density Jc decreases quite drastically by almost two orders of

magnitude when the doping p, the number of holes per Cu atom, decreases from 0.20 to 0.09 [2]. We

argue that these systematic but unconventionally puzzling doping behaviors can be explained as a

whole in terms of a model in which the Fermi arcs [3] in the underdoped region and the d-wave

symmetry of the order parameter are taken into account in a combined manner in the wave vector

space (k-space). This presents a picture of an inhomogeneous superconducting order parameter in the

k-space. In this model, itinerant holes reside in a limited angular range in the k-space centering in the

direction of the line node of the d-wave order parameter, i.e., (, ) direction. In the other ranges, the

density of states are absent at the chemical potential and the carriers need an extra energy to be

itinerant, forming a pseudogap. The angle that delineates these two ranges changes depending on the

doping level and makes a parameter that describes the characteristic doping dependence revealed

experimentally. Based on this model, numerical calculations are made to estimate the doping

dependence of Jc and the quasiparticle current-voltage characteristics for both an SIS and an SIN

tunnel junctions. The results give a qualitatively good agreement with the experimental results,

implying that the present model is well compatible with the high-Tc superconductivity mechanism to

be explored.

References

[1] R. Kleiner, F. Steinmeyer, G. Kunkel, and P. Müller, Phys. Rev. Lett. 68, 2394 (1992).

[2] M. Suzuki, T. Hamatani, Y. Yamada, K. Anagawa, and T. Watanabe, J. Phys. Conf. Ser. 150,

052252 (2009).

[3] W. S. Lee, I. M. Vishik, K. Tanaka, D. H. Lu, T. Sasagawa, N. Nagaosa, T. P. Devereaux, Z.

Hussain, and Z. –X. Shen, Nature 450, 81 (2007).



75

Explanation of the Meissner effect in Nano Josephson Junctions

by the Quantum Entanglement of the Landau States

M. Saglama*

, L. G. Boussiakoub, L. Babsail

b, S. Alsaleh

b and A. Al-Modlej

b

a Department of Physics, Ankara University, 06100 Tandogan, Ankara, Turkey

b Department of Physics and Astronomy, King Saud University , Riyadh 11495 Saudi Arabia



Phone: +90-312-2126720, Fax: +90-312-2232395

[keywords] Meissner effect, Quantum entanglement, Landau quantization, Magnetic length.

Meissner effect is one of the well known properties of superconductors [1]. When a

superconducting ring is placed in a week magnetic field, the field lines are expelled from the

superconductor and the magnetic flux through the ring takes the values 0n . Here

215

0 .100678.2)2( mTxeh is the unit of flux (fluxoid) and n is a non-zero

integer ,...)3,2,1( . For classical superconductors, London and London[2] explained the Meissner

effect by using a classical model based on Maxwell equations and minimizing the associated free

energy. The calculated penetration depths were in the range of ( mm 10010 ). Therefore when

the planar size of the superconductor becomes comparable with 2 the above mentioned classical

model becomes inapplicable. Because of the growing need to reduce the sizes into sub-micrometers

[e.g. for quantum computers and superconducting quantum intereference devices (SQUID)], we

develop a quantum model which is based on the quantum entanglement [3] of the Landau states of

electrons and holes in the system. Because of the Zeeman energy term )4/( *

cZeeman gE in

quantized Landau energies [4] given by )2/1(( nELandau , we will have entanglements of the

states resulting zero total spin. Here meBc is the cyclotron angular frequency and g is the

effective Landé-g factor and is treated as a varying parameter. A dimensionless function:

cZeemanLandau EEgnf /][),( * which takes the form: )4/2/1(),( ** gngnf is defined.

The plots of ),( *gnf with respect to g shows that

g takes only even integer values such as

...6,4,2,0 . In our model the magnetic length, eBl / is an important parameter which defines the

critical values of the inner and the outer diameters of the superconducting rings for the external

magnetic field, B . The present model explains the Meissner effect very well and can be easily

extended to the intrinsic quantum Josephson junctions as well.

References

[1] W. Meissner and R. Oschenfeld, Naturwiss.21, 787 (1933)

[2] F. London and H. London, Proc. R. Soc. London A149, 71 (1935)

[3] L. Babsail, L.G. Boussiakau, S. Alsaleh and M. Saglam, J. of Mod. Phys. 2 752(2011).

[4] M.Saglam, Physica E,v.17, 345 (2003).



76

Optimal Condition for Strong Terahertz Radiation based on


Feng Liua, b

, Shi-Zeng Lina, and Xiao Hu

a, b*

a International Center for Materials Nanoarchitectonics (WPI-MANA),

National Institute for Materials Science, Tsukuba, Japan b

Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Japan



Phone: +81-29-860-4897, Fax: +81-29-860-4706

[keywords] Intrinsic Josephson Junctions, terahertz radiation, dielectric material.

It has been known for a long time that the Josephson junctions can work as oscillators to excite high

frequency electromagnetic (EM) waves. The intrinsic Josephson junctions (IJJs) in Bi2Sr2CaCu2O8+d

(BSCCO) single crystal provides a good candidate for a solid state source of terahertz (THz) radiation.

An experimental breakthrough was achieved in 2007, where coherent THz EM waves were excited

successfully based on the IJJs of BSCCO mesa [1]. Two of the present authors proposed a novel kink

state which can explain the important experimental results [2, 3].

In the experimental setups to date, the radiation power is still too weak for practical uses due to the

small thickness of BSCCO mesa. In order to overcome this difficulty, we study a long cylindrical

BSCCO single crystal embedded in a dielectric material [4]. By doing this, on one hand we can have a

cavity, and on the other hand we can enhance the radiation energy by increasing the radiation area. It

is found that the radiation power reaches its maximum when it equals the dissipation caused by

Josephson plasma, a case of Jacobi’s law. This yields the optimal dielectric constant of the wrapping

material for a given superconductor, and also the maximal radiation power, which is proportional to

the product of the critical superconducting current squared and the normal resistance, with its apparent

form similar to the Ohm's law. Our analysis offers a guideline for choosing superconductor as a source

of strong radiation.

*This work is supported by WPI initiative on Materials Nanoarchitectonics, MEXT of Japan and by

CREST, JST.

References

[1] L. Ozyuzer et al., Science 318, 1291(2007)

[2] S.-Z. Lin and X. Hu, Phys. Rev. Lett. 100, 247006(2008)

[3] X. Hu and S.-Z. Lin, Supercond. Sic. Technol. 23, 0530021(2010)

[4] F. Liu, S.-Z, Lin and X. Hu, in preparation for submission.



77

Fabrication of standing bridge bolometer based on thinned single

crystal of Bi2212

A. Kokabia, A. Moftakharzadeh

a, H. Alaboz

b, L. Ozyuzer

b, N. Miyakawa

c,

M. Fardmanesha

a Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran

b Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey

cDepartment of Applied Physics, Tokyo University of Science, Tokyo, Japan



Phone: +90-232-7507705, Fax: +90-232-7507707

[keywords] hotspot bolometer, terahertz detection, BSSCO thin film.

The freestanding bridge structure of a bolometer made of thin single crystal Bi2Sr2CaCu2Ox

(Bi2212) for high sensitive terahertz radiation detection have been fabricated. To construct the device,

a single crystal of Bi2212 is thinned using double-sided cleaving technique. This approach allows

possibility of having a free standing structure by separation between the film and the substrate after the

cleaving and pattering process. The obtained patterned thin film from our cleaving process is floated

over a chemically etched silicon trench with the capability of holding the four edges of the suspended

film to prevent crystal damage. Applying the single crystal of Bi2212 in such a structure has the

advantages of the excellent film quality and the enhanced optical absorption along with the exclusion

of the substrate effect, which results in reduced floating mass and ultimate sensitivity from this

prospective. The optical response and the sensitivity of the device are measured using the four-probe

technique. The effects of the electrical bias on the optical response and the temperature dependence of

sensitivity of the device are also investigated.

References

[1] S. Cibella, P. Carelli, M.G. Castellano, V. Foglietti, R. Leoni, M. Ortolani, G. Torrioli, J

Low Temp. Phys. 154, 142 (2009). [2] X. Wang, L.X. You, D.K. Liu, C.T. Lin, X.M. Xie, M.H. Jiang, Physica C 474, 13 (2012).

[3] Y. Yamada, T. Watanabe, and M. Suzuki, IEEE Trans. Appl. Supercond. 17, 3533 (2007).



78

Chaotic Features of Coupled Josephson Junctions

Yury Shukrinov a

, Mohammad Hamdipour a,b

, Mohammad R. Kolahchi b

* ,

André E. Bothac, Minoru Suzuki

d.


b Institute for Advanced Studies in Basic Sciences, P.O.Box 45195-1159, Zanjan, Iran

c Department of Physics, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa d Photonics and Electronics Science and Engineering Center and Department of Electronic Science

and Engineering, Kyoto University, Kyoto 615-8510, Japan



Phone: +98-241-4152113, Fax: +98-241-4152104

[keywords] Intrinsic Josephson Junctions (IJJ), Chaos, Phase Dynamics, CCJJ+DC Model, Current-

Voltage Characteristics (CVC), Breakpoint Region (BPR), Longitudinal Plasma Wave

A system of Josephson junctions (JJs) is one of the prospective elements for superconducting

electronics and is currently being investigated intensively [1,2]. Here we show that a stack of coupled

Josephson junctions is capable of demonstrating some interesting and possibly useful behavior. Our

numerical simulations of the dynamics give Lyapunov exponents which indicate hyperchaotic

behavior in the resonance region.

The manifestation of chaotic behavior of coupled Josephson junctions in different physical

situations is analyzed. We show the variation

of the chaotic features in the breakpoint region

(BPR) of the current-voltage characteristics

(CVC) with dissipation parameter and

provide examples of the chaotic behavior

through the use of correlation functions and

polar diagrams. Our Studies of the effect of

the number of junctions in the stack and the

boundary conditions have allowed us to

observe a transition from the chaotic to the

regular regime.

To clarify the chaotic features in

coupled JJs, the linearized equation for the

phase differences is analyzed. There are

indications that chaotic behaviour may be

avoided by exploiting the parametric

resonance features of the model.

In the accompanying figure we present the CVC of the stack with nine JJs in the parametric

resonance region, together with the time dependence of the electric charge in the superconducting

layer and the Lyapunov exponent as a function of the bias current. We see that at point C1 the maximal

Lyapunov exponent turns positive, indicating chaos in the system.

References

[1] R. Kleiner, F. Steimmeyer, G. Kunkel and P. Mueller, Phys. Rev. Lett. 68, 2394 (1992).




79

Study of The Various Shapes of Mesas for Tunable, Coherent and

Continuous Terahertz Waves Emission in Intrinsic Josephson

Junctions Bi2Sr2CaCu2O8+δ

Kaveh Delfanazari a,b,c,*

, M. Tsujimoto a,b,c

, T. Kashiwagi b,c,d

, H. Asai b,c,d

, T. Yamamotoe

M. Sawamura a,b,c

, T. Kitamura a,b,c

, R. Nakayama a,b,c

, K. Ishida a,b,c

, H. Minami b,c,d

,

R.A. Klemm f, T. Hattori

b,d, and K. Kadowaki

b,c,d

aGraduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan

bCREST-JST,

cWPI-MANA

dFaculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan

eSemiconductor Analysis and Radiation Effects Group, JAEA, Japan

fDepartment of Physics, University of Central Florida, USA



Phone: +81-29-8535035, Fax: +81-29-8535035

[keywords], Intrinsic Josephson junctions, terahertz waves, cavity resonance.

Terahertz (THz) science is growing as a new branch of science in recent years [1]. Intense,

coherent and tunable THz radiation from intrinsic Josephson junctions (IJJs) in layered high

temperature superconductor has been reported recently [2] in which the mechanism of emission is

explained by two essential phenomena; the ac-Josephson effect as well as the cavity resonance. Most

of measurements have been done based on the rectangular mesas although disk and square mesas are

also studied [3]. All cases have normally linear polarization. Furthermore, the role of the mesa shape is

found to be as a cavity resonator that can enhance the radiation intensity. For further understanding the

role of the cavity for THz emission in IJJs, we performed mesas with various geometries by using the

focus ion beam (FIB) milling technique. Triangular mesas; isosceles, equilateral and right angled [4],

pentagonal, hexagonal and elliptical mesas with various sizes are fabricated. These shapes of mesas

are interesting to study because of their features for circular polarization which is noticeable for

designing the mesa array. We performed the experiment by measuring the temperature dependence of

the c-axis resistance, IV, temperature dependence of the outermost IV characteristics and spectra by

using the FT-IR spectrometer. We have analyzed our experimental data by comparing to the theory of

the patch antenna. In this symposium we will discuss our recent experimental data especially for

hexagonal mesas in which resonant frequency is inversely proportional to the side of the hexagonal

mesa.

*This research is supported partly by CREST-JST (Japan Science and Technology agency),

WPI (World Premier International Research Center Initiative)-MANA (Materials

Nanoarchitectonics) project (NIMS) and Strategic Initiative Category (A) at the University of

Tsukuba.

References

[1] M. Tonouchi, Nature Photonics 1, 97 (2007).

[2] L. Ozyuzer, et al., Science 318, 1291 (2007). K. Kadowaki, et al., Physica C 468 634 (2008).

[3] M. Tsujimoto, et al., Phys. Rev. Lett. 105 037005-1 (2010).

[4] K. Delfanazari, et al., JPCS, to be published 2012. K. Delfanazari, et al., to be published.



80

Electro-resistance characteristics in Sm0.55Sr0.45MnO3

Rajneesh Mohana, S. Saini

b, S. J. Kim

a,*

a Department of Mechatronics Engineering, Jeju National University, 690756, Jeju, Repulic of Korea

b Institute for Sustainable Sciences & Development, Hiroshima University, Hiroshima, Japan



Phone: +82-64-7543715, Fax: +82-64-7563886

[keywords] Intrinsic electro-resistance, Joule heating

The hole doped rare-earth perovskite manganites, RE1−xAExMnO3 (RE denotes rare-earth element

and AE denotes alkaline-earth element), have fascinated materials scientists all over the world for one

and half decades due to their interesting properties like colossal magnetoresistance, colossal

electroresistance charge ordering and electronic phase separation [1-4]. The electronic and magnetic

states of these manganites can be tuned by chemical composition, strength of magnetic field, strength

of electric field, temperature and pressure. The electric field/current dependent electrical resistance of

a manganite, i.e., electroresistance is of scientific interest and offer great opportunities for new

electronic devices e.g., in nonvolatile electronic data storage [5].We report the electrical characteristics

of Sm0.55Sr0.45MnO3 at different current biasing. The resistivity–temperature behavior has been

measured with different biasing currents (1 µA, 10 µA, 1mA, 5 mA, 10 mA) in constant biasing mode.

With increasing biasing current, the resistivity of the samples decreases drastically with shifting of

Metal to insulator transition temperature (TMI) towards lower temperature. The current voltage

characteristics of the sample were measured in the metal to insulator transition region. Time evolution

of resistance of the sample in the metal to insulator transition region was also studied under various

current biasing. The change in resistivity of sample was discussed in intrinsic electro-resistance and

joule heating effects.

References

[1] C.N.R. Rao and B. Raveau, Colossal Magnetoresistance, Charge-Ordering and Related

Properties of Manganese Oxides, World Scientific, Singapore, 1998.

[2] Y. Tokura, Colossal Magnetoresistive Oxides, Gordon and Breach, New York 2000.

[3] E. Dagotto, Nanoscale Phase Separation and Colossal Magnetoresistance, Springer, Berlin, 2003.

[4] R Mohan, N. Kumar, B. Singh, S. Bhattacharya, S. Rayaprol, A. Dogra, N. K. Gaur, S. K. Gupta,

S. J. Kim, and R. K. Singh, J. of Alloys & Comp. 508 (2010) L32-L35

[5] J.M.D. Coey, M. Viret, S. von Molnair, Adv. Phys. 48 (1999) 167-192.



81

Microwave responses in a-axis oriented Y123/Pr123 stacked junctions

S. Sainia,b

, M. Mukaidac, S.-J. Kim

d,*

aDepartment of Mechanical System Engineering, Jeju National University, South Korea,

bInstitute for Sustainable Sciences and Development, Hiroshima University, Japan.

cDepartment of Material Science and Engineering, Kyushu University, Japan,

dDepartment of Mechatronics Engineering, Jeju National University, South Korea



Phone: +82-64-7543715, Fax: +82-64-7563886

[keywords] multi layered thin films, a-axis oriented Pr123, flux flow behavior

The multi layered thin films of a-axis oriented YBa2Cu3O7 (Y123) and a-axis oriented

PrBa2Cu3O7 (Pr123) were grown alternately on SrLaGaO4 (100) substrate using pulsed laser deposition

[1]. When the current direction is perpendicular to the substrate this alternate structure gives

Josephson junctions phenomenon. The resistance vs. temperature (R-T) characteristics show transition

temperature of 71 K with the transition width (∆Tc) of 4 K for multilayered thin film. We have

fabricated a two-stacked device using three dimensional focused ion beam (3-D FIB) etching process

[2] which has artificial Josephson junctions. The value of ∆Tc for the device is found higher than bare

multilayered thin film which can be the effect of ion irradiation during the fabrication process. The

critical current density of 2.2 × 105 A/cm

2 is calculated from current-voltage (I-V) characteristics of

the device at 20 K. We notice suppression in critical current as the effect of external microwave at

different power. As we increase the power, the superconducting state is suppressing and resulting to

suppress the critical current. The voltage steps in I-V characteristics for the device are proportional to

the power of external microwave at 10 GHz. The value of voltage step indicates flux flow behavior of

the junctions [3].

References

[1] S. Horii, M. Takamura, M. Mukaida, A. Ichinose, K. Yamada, R. Teranishi, K. Matsumoto, R.

Kita, Y. Yoshida, J. Shimoyama, and K. Kishio, Appl. Phys. Lett. 92, 132502 (2008).

[2] S.-J. Kim, I. Yu. Latyshev, T. Yamashita, Supercond. Sci. Technol. 12, 729 (1999).

[3] S.-J. Kim, H. Myoren, J. Chen, K. Nakajima, T. Yamashita, and M. Esashi: Jpn. J. Appl. Phys. 36,

L 1096 (1997).



82

Influence of LCR Shunting in Current-Voltage Characteristic of


Ilhom Rahmonova,b*

, Yury Shukrinova,b,c

, Kirill Kulikova,c

and Karim ElGammald

a

BLTP, Joint Institute for Nuclear Research, Dubna,141980, Russia b Umarov Physical Technical Institute, Tajik Academy of Science, Dushanbe, Tajikistan

c Department of Theoretical Physics, International University of Dubna, Dubna, 141980, Russia

d Nanotechnology Research Center, Nile University, Smart Village, Cairo,12677 Egypt


E-mail address: [email protected], [email protected]

Phone: +7-49621-64534, Fax: + 7-49621-65084

[keywords] intrinsic Josephson junctions, terahertz waves, longitudinal plasma wave, resonance

frequency.

The intrinsic Josephson junctions (IJJ) in high TC

superconductors can be used as terahertz electromag-

netic waves sources in the superconducting electronics

[1]. One of the important problems is to synchronize all

junctions in a stack. Some theoretical models were

proposed which demonstrated that resistive-inductive -

capacitive (RLC) shunting leads to synchronization all

junctions [2, 3]. When J=2LPW, where J and LPW

are Josephson and longitudinal plasma wave

frequencies, respectively, a parametric resonance in the

system is appeared and amplitude of the electric charge

in the superconducting layers is increased [4].

We study the phase dynamics of the IJJ stack shunted

by RLC resonant circuit in the framework of models

with capacitive coupling [5,6] and discuss the influence of RLC shunting on CVC and

parametric resonance in the system. The case of R shunting is demonstrated in the Figure. We

see that parametric resonance region is shifted with changing of the resistance value. The

same value of resonance voltage means that longitudinal plasma wave frequency doesn’t

change in this case. In the case of LC shunting the step structure in CVC appears, when the

value of Josephson frequency approaches to the frequency of the LC circuit [2,3]. The

location of the step structure depends on parameters of the LC circuit. The influence of

parametric resonance on this feature is investigated in detailed.

References

[1] L. Ozyuzer et al, Science, 318, 1291, (2007).

[2] M. Tachiki, K. Ivanovic, K. Kadowaki, T. Koyama, Phys. Rev. B, 83, 014508 (2011)

[3] T. Zhou, J. Mao, H. Cui, X. Zhao, L. Fang, S. Yan, Physica C, 469, 785 (2009)

[4] Yu. M. Shukrinov and F. Mahfouzi, Supercond. Sci. Technol., 20, S38-S42 (2007)

[5] M. Machida, T. Koyama, A.Tanaka, and M.Tachiki, Physica C, 330, 85 (2000)

[6] Yu. M. Shukrinov, F. Mahfouzi, P. Seidel, Physica C, 449, 62 (2006)

Figure. CVC in the case of R-shunt:

α-coupling parameter; β-dissipa-

tion parameter; bR-dimensionless

resistance.



83

Vortex dynamics in self-dual Josephson junction arrays near the

quantum critical point.

Said Sakhi

College of Arts and Sciences, American University of Sharjah,

P.O. Box 26666, Sharjah, UAE


Phone: +97165152508, Fax: +97165585066

[keywords] Josephson Junction arrays, Vortex dynamics, Hall effect.

Planar arrays of Josephson junctions (JJA) display rich quantum phenomena due to two competing

couplings: EJ the Josephson energy associated with tunneling of Cooper pairs between islands, and EC

the charging energy required to add extra charges to neutral islands. The low energy effective field

theory of this model is described within the framework of a mutual Chern-Simons Landau- Ginzburg

theory and consists of two complex fields coupled to two fluctuating gauge fields, leading to nontrivial

dynamics. The electromagnetic response functions are obtained at its quantum critical point. The

source of dissipation originates from the underlying dynamics of gapless bosonic excitations

interacting with the gauge fields representing the current of Cooper pairs and vortices. For unfrustrated

JJA systems, with lone excited charge-like modes, I find a universal conductivity which agrees with

previous findings. When both charge-like and magnetic-like gapless modes are concurrently excited I

find a new universal conductivity with a reduced value. In the presence of commensurate frustration

due to offset charges and external magnetic fields, I find a universal longitudinal resistance at the

critical point as well as a quantized Hall resistance. This is in contrast with earlier attempts that found

that magnetic frustrations, similarly charge frustrations, prevent in general the appearance of a

universal resistance at the transition since the gap remains finite up to the transition. The crucial point

here depends on the commensurability between the charge and magnetic frustration which guarantees

a vanishing background field seen by composite fields, resulting in gapless modes at the transition.

This new approach sheds a new light on the origin of the Hall effect in JJA systems. The quantization

of the Hall resistance is robust in the presence of quantum dissipation and the ensuing longitudinal

resistivity is finite.

References

[1] S. Sakhi, J. Phys. A: Math. Theor. 41, 085003 (2008).

[2] S. Sakhi, Phys. Rev. B 73, 132505 (2006)

[3] S. Sakhi, Journal of Low Temperature Physics: Volume 158, 631 (2010).



84

Searching for Doping Level of High Temperature

Superconducting Bi2Sr2CaCu2O8+δ Crystals

for Powerful THz Emission

Yasemin Demirhana*, F. Turkoglu

a, H. Saglam

a, H. Koseoglu

a, M. Minematsu

b,

H. Arakib, N.Miyakawa

b, T. Yamamoto

c, K. Kadowaki

c L. Ozyuzer

a

a Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey

b University of Tsukuba, Tsukuba, Japan

c Department of Applied Physics, Tokyo University of Science, Tokyo, Japan



Phone: +90-232-7507683

[keywords] Intrinsic Josephson Junctions, terahertz waves

Rapidly increasing applications of the electromagnetic waves in the under developed terahertz

frequency range requires a well understood technique of efficient terahertz wave generation. Our

previous results show a strong feasibility of developing high efficiency terahertz wave radiated

devices that have non ionizing nature and frequency tunability[1]. A striking contrast to the previous

results was that emission does not require the application of a magnetic field, considerably simplifying

the desing of superconducting THz sources.

In layered high temperature superconductors like Bi2212, superconductivity is controlled by

carrier doping of the conducting CuO planes. Furthermore artificial junctions always have slightly

different junction parameters, especially the Josephson critical current that leads to desynchronization

and dramatic drop in emission power. By changing the doping level of the crystals, critical

temperature, c-axis resistivity and critical current of IJJs can be tuned in a range from underdoped to

overdoped region. It is shown that the THz emitting mesas are below a certain underdoped level,

which has relatively small critical current in contrast to optimally doped and overdoped Bi2212 [2].

Because of small critical current, large area mesas fabricated from underdoped crystals cause less

heating and backbending occurs after the cavity resonance in voltage scale. So, Powerful THz

radiation can be obtained before heating severely affects the local mesa temperature.

In this study, under optimized doping conditions we aimed to investigate powerful terahertz

emission. We fabricate triple rectangular-shaped mesa structures with same area on the Bi2212 crystal

and investigate the correlation between crystal homogenity and doping levels with electrical

characterizations. In order to characterize the Bi2212 mesas, by three probe contact c-axis resistance

versus temperature (R–T), and current–voltage behavior (I –V) were measured in a He flow cryostat.

*This research is partially supported by TUBITAK (Scientific and Technical Research Council of

Turkey) project number 110T248.

Refrerences


[2] L. Ozyuzer et al, Supercond. Sci. Technol. 22, 114009 (2009).



85

Terahertz Emission from Rectangular Mesa Structures of

Superconducting Bi2Sr2CaCu2O8+δ

F. Turkoglu1, L. Ozyuzer

1, H. Koseoglu

1, Y. Demirhan

1, Y. Simsek

2, S. Preu

3, D. Ploss

3,

S. Malzer3, H. B. Wang

4, P. Müller

2

1 Department of Physics, Izmir Institute of Technology (IZTECH), 35430, Izmir, Turkey,

2 Physical Institute III, University of Erlangen-Nurnberg, Erlangen, Germany,

3 Max Planck Optics Group, University of Erlangen-Nurnberg, Erlangen, Germany,

4 National Institute for Materials Science, Tsukuba, Japan



Phone: +90-232-7507721


There is an increasing interest in science and technology of electromagnetic waves in terahertz

frequency range (0.1-10 THz) because of their emerging application areas including physics, biology,

chemistry, astronomy, medicine etc. [1]. The observation on generation of THz radiation emitted from

lateral dimension of high temperature superconductor (HTS) Bi2Sr2CaCu2O8+δ (Bi2212) and responses

to THz waves increase the importance of these HTSs [2]. Single crystal of HTS Bi2212 forms natural

superconductor-insulator-superconductor (SIS) layered junctions, which are called intrinsic Josephson

junctions (IJJ). The stacks of IJJs in Bi2212 can be used such a voltage-frequency converter and their

large energy gap allows the emissions at THz frequency range. Recently, it is demonstrated that

rectangular IJJ mesa structures of Bi2212 can be used as a source of continuous, coherent and

polarized THz radiation [2].

In this work, rectangular Bi2212 mesa structures were fabricated on as-grown Bi2212 single crystals

using standard photolithograph and Ar ion beam etching techniques. In order to characterize the

Bi2212 mesas, c-axis resistance versus temperature (R-T) and current-voltage behavior (I-V) were

measured in a He flow cryostat. During I-V characterization, Si composite bolometer was used to

detect the THz emission. THz emission characteristics of one of the 60x300 µm2 mesa at 22 K show

that bolometer signal is increasing at high bias region of I-V curve. It indicates that local mesa

temperature is increasing and bolometer detects the heating of the mesa. THz emission was obtained

before heating severely affects the local mesa temperature, near 0.61 V. In contrast to previous studies,

emission frequency was determined using interferometer set up instead of FTIR. The radiation was

still detected outside the cryostat after traveling long way through ambient space. This is only possible

since the power emitted from this device is strong.

This research is supported in part by the TUBITAK (Scientific and Technical Council of Turkey)

project no. 110T248.

References [1] M. Tonouchi, Nature Photonics 1, 97-105 (2007)

[2] L. Ozyuzer et al., Science 318, 1291 (2007)



86

Reactive Ion Etching of Superconducting Bi2212 using PRʹ/Ta/PR

and Ta/PR mask for the THz Waves Emission

Hasan Koseoglu1, Fulya Turkoglu

1, Yasemin Demirhan

1, Lutfi Ozyuzer

1

1Department of Physics, Izmir Institute of Technology, 35430, Izmir



Phone: +90-232-7507721

[keywords] Intrinsic Josephson Junctions, RIBE, THz Radiation

High temperature superconducting Bi2Sr2CaCu2O8+δ (Bi2212) single crystals have natural

junctions called intrinsic Josephson Junctions (IJJs). They play an important role for generation of

THz radiation when a static voltage is applied along the c-axis of Bi2212 (ac Josephson effect) [1, 2].

Generation of powerful THz radiation requires mesas with large lateral dimension but there are

difficulties in fabrication of perfect rectangular mesa. It should be close to 90 degrees to obtain IJJs

with same planar dimensions for synchronization of IJJs [3].

Thick photoresist (PR) layer (single layer mask) shades the lateral dimension of mesa during ion

beam etching. Therefore, we patterned multilayer masks on Bi2212 and used selective ion etching to

overcome this problem [4]. Therefore, in this study, to fabricate the smooth rectangular prism shape

with large area, high thickness and high lateral angle, we used three different masks that are single

layer mask and two different multilayer masks, which are Ta/PR and PR'/Ta/PR [5].

During the mesa fabrication, thermal evaporation was used to deposit the Au layer. Ta layer was

deposited by DC magnetron sputtering. Photolithography process was applied to cover the PRʹ layer

and pattern the mesa shaped PR. After the preparation of the mesa shaped PR pattern, reactive ion

beam etchings have been done with the ion beam of Ar, N2 and O2 and we have obtained mesas with

almost 1 µm thick and high lateral angle.

The mesas dimensions were characterized using AFM and THz cryostat system was used to

examine electrical properties (R-T and I-V) of mesas. During I-V measurements, the bolometric

measurements were done to detect emission from the Bi2212 superconducting mesas.

This research is supported in part by the TUBITAK (Scientific and Technical Council of Turkey)

project no. 110T248.

References [1] L. Ozyuzer et al., Science 318, 1291 (2007)

[2] X. Hu et al. Supercond. Sci. Technol. 23, 053001 (2010)

[3] A. E. Koshelev et al., Phys. Rev. B 77, 014530 (2008)

[4] Y. Nagai et al., IEEE Transactions on Magnetism 27, 1622 (1991)

[5] H. Koseoglu et al. J. Supercond. Nov. Magn. 24, 1083–1086 (2011)



87

Fabrication of Triple Mesa Structures from

High Temperature Superconducting Bi2Sr2CaCu2O8+δ (Bi2212)

for Terahertz Emission

Hilal Saglama*, Y. Demirhan

a, H. Koseoglu

a, F. Turkoglu

a, H. Alaboz

a, K. Kadowaki

b,

L. Ozyuzera


bUniversity of Tsukuba, Tsukuba, Japan



Phone: +90-232-7507684


There are numerous application fields of terahertz waves such as airport screening of passengers for

weapons, explosives, drugs, secure wireless communications, cancer detection, etc. High-Tc

superconductor Bi2Sr2CaCu2O8+δ (Bi2212) single crystal has been observed as an intense, coherent,

continuous electromagnetic wave source in terahertz frequency region [1]. Bi2212 which is highly

anisotropic high-Tc superconductor is considered as a stack of intrinsic Josephson junctions (IJJs) on

atomic scale [2]. In this study, we have fabricated triple mesa structures on a same chip with various

mesa surface areas. Firstly, single crystal of Bi2212 is glued onto a sapphire substrate from its smooth

a-b surface by silver epoxy. After deposition of 100 nm Au layer, rectangular mesa structures were

fabricated on the surface of an underdoped Bi2212 crystal by using e-beam lithography and Ar-ion

etching step by step. On account of the difficulties in making a contact on small area of the mesa, CaF2

insulating layer deposition was performed. After that, a gold stripe with the width of 30 μm was

created by lift-off technique on the mesa and CaF2 layer. Finally three gold probe wires were

connected to the two contact paths and mesa by silver epoxy. After the mesa fabrication, the exact

dimensions of the mesas were obtained using atomic force microscope. To obtain the electrical

characterization, c-axis resistance versus temperature (R-T), and current-voltage behavior (I-V) were

measured. From I-V characteristics, critical current of each mesa structure having different dimension

was obtained, after that we have calculated the critical current densities of each mesa structure. We

investigated relation between current density and surface area, and their effect on THz emission.

*This research is partially supported by TUBITAK (Scientific and Technical Research Council of

Turkey) project number 110T248.

References


[2] R. Kleiner et al., Phys. Rev. Lett. 68, 2394 (1992).



88

The Wide Band Radar Absorbing Epoxy Composites

with Metal Coated Glass-Fiber Fabrics

M. D. Yamana,*

, L. Ozyuzera,

S. Kangalb, M. Tanoglu

b


b Department of Mechanical Engineering, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey



Phone: +90-232-7507705, Fax: +90-232-7507707

[keywords] Thin film coating, radar absorbing materials, microwave absorbers.

Electromagnetic waves in the GHz range are being increasingly used in wireless communication

tools, local area networks, radar systems and other communication equipments. More effective

absorption properties that can be used as radar absorbing materials for military applications, therefore

there is a strong demand on microwave absorbing materials with wider absorption bandwidth.

The purpose of this work is to design absorbing plates with double-layer materials composed of

ferroelectric and ferromagnetic materials as absorbents in epoxy filler in order to improve the

electromagnetic absorbing properties of wave plates which have wider absorption bandwidth and

lower reflection loss than the single-layer microwave absorbers. The way for fabrication of this type of

device was started by coating of chromium on glass-fiber surface by large area magnetron sputtering

system. The surface resistances of the coated thin chromium layers were varied about 13.8x10-5

ohm/sqr. Cr coated glass-fiber material as a matching layer is required to reach the value of the free

space permittivity which is 377 Ω. A material with an impedance of 377 ohms don’t reflect

microwaves if the incident medium is free space, in this way most of the incident wave can enter the

inside of the layer[1].

For a design of good absorbing material, attenuation is another condition that should be

satisfied. As incident wave propagates in to the absorbing medium, it should get rapidly attenuated

through the material layer and inside of the first and second layers [2, 3]. To reach maximum

absorption, we used some powder addends like carbonyl iron and barium ferrite that are promising

absorbents. Here, we used epoxy as a matrix binder. To achieve the maximum absorption, we

calculated the optimum values of complex permittivity ( - ) and permeability ( - )

theoretically using transmission line theory [4]. Then, we tried to catch these values in our

experimental studies of multi-layers. We also tabulated the change of values of ε and μ depending on

the coming microwave frequency. Perfect impedance matching can also be realized if the electric

permittivity and the magnetic permeability are equal.

Other consideration of this research is the effect of the thickness of the layer on the absorption

conditions. When we change the thickness, the absorption properties of the layers also change. For this

reason, we tried to optimize the thickness for maximum absorption in the frequency range of 2-18

GHz.

References

[1] K. J. Vinoy and R. M. Jha. 1996 Boston, MA: Kluwer- Academic

[2] Y. B. Feng, T. Qui, C. Y. Shen, X. Y. Li, IEEE Trans. Mang. 42 (3) (2006) 36.

[3] T. Kagotani, R. Kobayashi, S. Sugimoto, K. Inomata, K. Okayama, J. Akedo, J. Magn. Magn.

Mater. 290-291 (2) (2005) 1442.

[4] Y. Michielssen, J. M. Sager, S. Ranjithan, R. Mittra, Microw. Theory Tech. 41 (1993) 1024-1031.



89

X-Ray Photoelectron Spectroscopic Analysis of HfO2/Hf/Si

Multilayer Structure Prepared by Radio Frequency Magnetron

Sputtering

A. Cantas*, G. Aygun

Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey



Phone: +90-232-7507695, Fax: +90-232-7507707

[keywords] Magnetron sputtering, HfO2, XPS, SE.

Having high dielectric constant (к) ~25, hafnium oxide (HfO2) is one of the best materials to be

replaced by common material of microelectronics, namely SiO2 [1]. In addition to its high dielectric

constant resulting in a huge application area in microelectronics, its large bandgap energy, high

refractive index, hardness as well as good transmissivity in the visible and ultraviolet range make it an

interesting material for also optical applications [2]. In this study, HfO2 thin film was grown on Si with

a rf sputtering system which a Spectroscopic Ellipsometry (SE) attached on it to define in-situ optical

characteristics of HfO2 thin film during growth. In order to avoid to formation of undesired interfacial

layer between thin HfO2 film and Si substrate, not only the native oxide on Si substrate was kept but

also a thin Hf metal was deposited prior to oxidization process. The crystalline structure of grown thin

HfO2 film was determined with X-Ray Diffraction (XRD). The composition, chemical states and its

interface with Si were analyzed by FTIR and XPS. Optical results showed that HfO2 film grown

linearly with deposition time. Refractive index of HfO2 film was obtained as 1.93 which is close to

bulk form of oxide film. XRD spectra indicated that the film has polycrystalline structure with

monoclinic phase of HfO2. The FTIR spectrum indicated the formation of thick hafnium silicate

interfacial region of this 6nm thick hafnium oxide film. The XPS depth profile analysis revealed the

existence of hafnium silicate (HfxSiyOz) layer before very thin SiOx interfacial layer [3]. The presence

of SiO2 and HfxSiyOz interface layers was also supported by FTIR analysis.

* This study was supported by a TUBITAK project (# 107T117) and a BAP project (#

2008IYTE37).

References

[1] G. Aygun et al, Thin Solid Film 519, 5820 (2011).

[2] J. Aarik et al, Thin Solid Film 466, 41 (2004).

[3] G. Aygun et al, Journal of Applied Physics 106, 014312 (2009)



90

Electrical and Optical Properties of Large Area Grown ITO

Sebnem Yazici1,*

, Ayten Cantas1, Mutlu D. Yaman

1,2, Hasan Koseoglu

1,

Hilal Saglam1, Gulnur Aygun

1, and Lutfi Ozyuzer

1,2

1Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey

2Teknoma Technological Materials Ltd., Izmir, Turkey



Phone: +90-232-7507695, Fax: +90-232-7507707

Keywords: Transparent Conducting Oxides, Surface Resistance, XPS

Among the transparent conducting oxides, indium tin oxide (ITO) is a material with low resistivity

(~10-4

ohm.cm), high transparency (~90%) [1]. As a result of these properties, ITO is transparent in

the visible and reflective in the infrared spectral regions. It is used as electrode in LCD displays,

photovoltaic cells, antireflection coating, heat reflecting mirror, transparent electromagnetic shielding,

optical sensor and opto-electronic device. The electronic and optical properties of ITO are strongly

dependent on the deposition conditions and post-deposition annealing process. Also, it is reported that

(211)-oriented films shows excellent wide spectrum transparency and highest conductivity comparably

highest surface energy [2]. In this study, we investigate annealing effects on crystallization of ITO,

Sn4+

activation conditions and oxygen vacancies of ITO films. The motivation for our research is to

optimize parameters for deposition and post-annealing procedure of ITO thin films by a magnetron

sputtering system and obtain (211) peaks by reducing sputtering ambient containing 0.25-0.5 % H2.

The ITO thin films having thickness of 230 nm were deposited using magnetron sputtering from a ITO

target (90:10 wt. % of In2O3 and SnO2) on large area glass substrate (50 cm x 90 cm). A number of

experimental analysis; XRD, ellipsometry, spectrophotometer and X-ray photoelectron spectroscopy

have performed. Main growth planes such as (222), (400), (440) and (622) which are related to the

cubic structure of In2O3 were detected from XRD analysis. It is found that interplanar distances,

average optical surface resistivity and transmission of the films have their optimum values when the

relative intensity of the (222)/(400) is equal to 1. Chemical states were examined by XPS to a

determination of the structure and functionalized surface layer. It was understood that, oxygen content

in the film is closely related to its band gap. After post-annealing procedure in addition to decrease in

resistivity, the mean transmission in visible light range was increased.

*This work is partially supported by TUBITAK (Scientific and Research Council of Turkey) project

number 112T068.

References

[1] O. Tuna, Y. Selamet, G. Aygun, L. Ozyuzer, Journal of Physics D: Applied Physics,

43, 055402 (2010)

[2] D. Wan, P. Chen, J. Liang, S. Li, F. Hung, ACS Appl. Mater. Interfaces, 3, 4751-4755 (2011)



91

Fabrication of Superconductive Bi2212 Hot Electron Bolometer

H. Alaboza, H. Köseoğlu a, A. Kokabib, M. Fardmaneshb,

N. Miyakawac, L. Ozyuzer a

aDepartment of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey bDepartment of Electrical Engineering, Sharif University of Technology, Tehran, Iran

cDepartment of Applied Physics, Tokyo University of Science, Tokyo, Japan


[keywords] hot electron bolometer, mechanical exfoliation, BSCCO thin film.

Terahertz (THz) wave’s ability to pass through clothing, packaging materials such as fabrics, plastics,

and cardboard, to reflect from metal and to be absorbed by water host significant potential applications

including shopping centers and airport security. Today, there are several constraints in different types

of bolometers [1,2] which are used for detection of THz waves e.g. they require very difficult and

costly cryogenic spending and slow response times. Hot electron bolometers (HBE) have a special

place among them because of their fast response time. Another advantage of HBEs is that arrays of

them could be placed on a single chip. HEB gets lots of interest and many different works have been

published [3,4]. In this work, we examined various methods for constructing hot electron bridge

bolometer. Bi2Sr2CaCu2O8+d (Bi2212) is a high Tc superconductor with special properties such as

high anisotropy and perfect crystal structure that makes it the best choice for this application.

Unfortunately, the qualities of Bi2212 thin films are far away from Bi2212 single crystals. We used

mechanical exfoliation technique [5,6] to obtain 100 to 500 nm think Bi2212 layers. These layers were

transferred to sapphire substrates which contain bow tie antenna like bridge. Resistivity versus

temperature data were obtained for these structures.

References

[1] A. Luukanena and J. Pekola, Appl. Phys. Lett. 82, 3970 (2003).

[2] P. L. Richards, J. Appl. Phys. 76, 1 (1994).

[3] R. Romestain, B. Delaet, P. Renaud-Goud, I. Wang, C. Jorel, J. C. Villegier and J. Poizat, New

Journal of Physics 6, 129 (2004).

[4] S. Cibella, P. Carelli, M.G. Castellano, V. Foglietti, R. Leoni, M. Ortolani, G. Torrioli, J. Low

Temp. Phys. 154, 142 (2009).

[5] Y. Yamada, T. Watanabe, M. Suzuki, IEEE Transactions on Applied Superconductivity 17, 2

(2007).

[6] X. Wang, L.X. You, D.K. Liu, C.T. Lin, X.M. Xie, M.H. Jiang, Physica C 474, 13 (2012).



92

Fabrication and Characterization of CZTS Absorber Layer on

Titanium Coated Ceramic for Solar Cells

M.A. Olgara,* H. Saglam

b, S. Yazici

b, A. Cantas

b, G. Aygun

b, E. Yanmaz

a, L. Ozyuzer

b

aDepartment of Physics, Karadeniz Technical University, Merkez, 61080, Trabzon, Turkey

b Department of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey



Phone: +90-462-3774194, Fax: +90-462-3253195

[keywords] Thin film solar cells, Cu2ZnSnS4 (CZTS) thin film

The thin film solar cell technologies receive increasing interest from the photovoltaic industry

because of the their potential producing low cost electricity compared to wafer based crystalline Si

technologies. Although CIS and CIGS such some important absorber layers and have maximum

efficiencies approaching %20 [1], they contain rare and expensive materials like In, Ga, Te and also

include toxic elements like Cd and Se that represent disadvantages. Cu2ZnSnS4 (CZTS) is a new

promising absorber layer for solar cell application which contains earth abundant elements and has an

absorption coefficient over 10-4

cm-1

and band gap energy near 1.45 eV [2]. In this study, we fabricate

and characterize CZTS absorber layer. We obtain CZTS structure in two stages. The first stage is

sequential metallic precursor layers by RF magnetron sputtering and the second stage is sulfurization

of these metallic multilayers. Due to the matching thermal expansion coefficient of titanium with

CZTS, we deposited Ti on ceramic substrate as a back contact layer. In addition, we observed that

titanium shows stronger adhesive force subject to the traditional back contact Mo on the surface of the

ceramic. Then we deposited metallic thin films layer by layer by order Cu, Zn and Sn with different

thickness. The individual thickness of each layer was measured by profilometer. In the second stage,

we perform the sulfurization process in order to complete the CZTS absorber layer [3]. The sulfur

solid source was heated to a particular temperature to obtain sulfur vapor. The sample was heated in

the Ar atmosphere in the presence of sulfur gas with particular time and temperature. Consequently

CZTS absorber layer was fabricated. The crystal structure of the CZTS was investigated by XRD, and

Raman Spectroscopy, thickness and morphology analysis were performed by SEM. Finally, the

chemical composition characterization was investigated by XPS.

*This work is partially supported by TUBITAK (Scientific and Research Council of Turkey) project

number 112T068.

References

[1] Ingrid Repins et al., Prog. in Photovolt.: Research and Applications 16, 235–239 (2008).

[2] J.M. Raulot et al., J Phys Chem Solids 66, 2019–2023 (2005).

[3] P.A. Fernandes et al., Thin Solid Films 517, 2519-2523 (2009).



93

Temperature Dependence of Ionic Conductivity in PVB/LiClO4

Halil Arslana, H. Saglam

a, M. D. Yaman

a, H. Koseoglu

a, H. Alaboz

a, G. Aygun

a,

L. Ozyuzera




Phone: +90-232-7507684

[keywords] Ionic Conductivity, PVB, LiClO4

Electrochromic glass which is also known as smart glass is an innovative and modern building

technology that can be used to create windows or skylights. Electrochromic glass allows users to

control the amount of heat or light that passes through the glass at the flick of a switch, giving them

the ability to regulate temperature or create privacy. These glasses utilize the principle of

electrochromism which allows certain materials to change color or even opacity when a burst of

charge is applied. While a small burst of electricity is required for changing the opacity of the glass, no

electricity is needed for maintaining a particular shade once the change has been observed. In principle

an electrochromic device consists of a transparent electrode of transition metal oxide deposited on a

conductive glass, ion conductor and a counter electrode. In general the reaction leading to darkening

and bleaching of the glass is a result of electron transfer accompanied by ion insertion or extraction,

polymers conduct with ions [1]. The ion-conducting PVB (Polyvinyl butral) interlayer was used

because of its unique properties such as high optical transparency, excellent toughness, flexibility and

high impact strength [2]. On the other hand, LiClO4 (Lithium perchlorate) was used to provide ionic

conductivity. LiClO4 which is an inorganic compound with white color is important for high solubility

in many solvent. It exists both in anhydrous form and as a trihydrate. In addition to these materials,

methanol (CH3OH) was used as solvent for obtaining ionic conductor materials. The samples were

prepared with different amount of LiClO4 (5, 10, 15 wgt%) and the measurement of samples was taken

using Agilent impedance analyzer in the frequency range of 40 Hz – 10 MHz. These prepared

samples were investigated at different temperatures (25, 40, 50, 60 and 70 °C). The result of

investigation shows that the ionic conductivity increases as the temperature increases.

References

[1] R. Reisfeld et al., Solar Energy Materials and Solar Cells 54, 109-12 (1998).

[2] H. Stenzel et al., Conference Proceedings Book, pp. 423-426, Glass processing days (2003).



94

Mechanical and Superconducting Properties of Ag- doped Bi-2223

Superconductors

E. Burcu Cevizci*, O. Bilgili, K. Kocabas

Department of Physics, Dokuz Eylül University,35160 İzmir, Turkey

Corresponding autor


Phone: 0(505)9415118

[keywords] BSSCO, superconducting properties, Vickers microhardness, AC susceptibility, Ag

doping.

A study have been made of the effect of Ag2O additions on the superconducting structural and

mechanical properties of Bi1.7Pb0.3Sr2Ca2Cu 3-xAgxOy (x =0.0, 003, 0.06, 0.09 and 0,12). Ag doped Bi-

2223 superconductors were obtained by conventional solid-state reaction method. AC magnetic

susceptibility measurements are made to investigate the superconducting properties. The critical

transation tempetures are found about 107, 108, 69, 71 and 68 K with increasing doping rate. Vickers

microhardness measurements are made to analyze the mechanical properties of samples. Scanning

electron microscopy (SEM) and X-ray diffraction ( XRD) were done to investigate the surface

microstructure of the samples and crystal structure determination, calculation of lattice parametres.



95

The influence of Nb Addition on Properties of Bi-2223

Superconductors

Ozlem Bilgili*, E. B. Cevizci, K. Kocabaş

Department of Physics, Dokuz Eylul University, 35160 Buca Izmir, Turkey



Phone: +90-537-3347906

[keywords] High-temperature superconductors, AC susceptibility, Nb addition,Vickers microhardness

The effects of addition of Nb2O5 on structural, superconducting, magnetic and mechanical

properties in Bi1.7-xPb0.3NbxSr2Ca2Cu3Oy superconductor with x=0,00, 0,05, 0,10, 0,15 0,20 were

investigated. The samples were prepared by standard solid-state reaction method in bulk forms. The

investigation consisted of X-ray diffraction (XRD), scanning electron microscopy (SEM), AC

susceptibility and microhardness measurements.

The lattice constants and volume fractions are estimated from XRD analysis. XRD data show that

the high-Tc phase increases and the low-Tc phase decreases as the Nb substitution changes from x =

0.0 to 0.2. Critical onset and loss peak temperatures were qualitatively estimated from the ac

susceptibility curves. The peak temperature at zero ac magnetic field and intergrain critical current

densities were theoretically calculated from the ac susceptibility plots via the critical state models. The

critical onset temperatures were observed to be about 108 K for Nb0, 105 K for Nb1, 104 K for Nb2,

105 K for Nb3 and 100 K for Nb4 sample respectively.



96

Index

Abdelhafiz H. …………..………… 55, 72

Alaboz H. …………….. 59, 77, 87, 91, 93

Aljumah A. A. ………….……………..71

Al-Modlej A. ……………………...…..75

Alsaleh S. ……………………..……….75

Anagawa K. …………………..………..74

Araki H. ………………..…….………..84

Arslan H. ……………..………………..93

Asai H. ……………..…...……..26, 37, 79

Asai I. ……………..…………………..24

Askerzade I. N. ………………………..68

Aygun G. …...……………..89, 90, 92, 93

Babsail L. ………………..……………..75

Benseman T. M. ……………..………. 34

Bilgili O. ……………..……..……..94, 95

Botha A. ……………..………...…..55, 78

Boussiakou L. G. ……………….……..75

Bulaevaskii L. N. ………….…………..30

Cantas A. ...……..……………..89, 90, 92

Canturk M. ……………..……………..68

Çataltepe O. A. ……………..…..……..67

Cevizci E. B. …………………..…..94, 95

Delfanazari K. ……………..24, 26, 36, 79

Demirhan Y. .…………..59, 84, 85, 86, 87

Dmitriev P. N. ……………..…………..38

Doh Y. J. …….……..…………….. 10, 52

Elgammal K. ..…………..…………55, 82

Fang L. ..…..……………..…………….63

Fardmanesh M. ………………..47, 77, 91

Fenton J. C. ……………..……………..50

Foda A. …………..……..……….....55, 64

Gaafar M. ...…...……..……………..55, 64

Galal A. ……………..……..…………..55

Galin M. ……………..……….………..35

Gray K. E. ……………..…………..33, 34

Gross B. ………………..…..25 32, 66, 73

Grünzweig M. ……………..…………..73

Guénon S. ……..…………..25, 32, 66, 73

Gulevich D. R. ……………….………..38

Hamatani T. ……………..…...………..74

Hamdipour M. …………..…..……..55, 78

Hamza E. …………………………..55, 72

Hassan H. F. ……………..………..…..38

Hatano A. ……………………………..27

Hatano T. ……...……....25, 32, 60, 66, 73

Hattori T. ……………..…...…………..79

He M. ………………………….………63

Hegab K. ……………..…..………..55, 72

Hinks D.G. ……………..….…………..33

Hirano T. ……………..………………..40

Hirata K. ……………..………………..61

Hirayama N. ……………..…………....45

Hu X. ……………..….………..28, 30, 76

Ichioka M. ……………………………..40

Iishi A. ……………..…...……..25, 32, 73

Irie A. ……………..…………….……..65

Ishida K. …………………………..26, 79

Ishii A. ……………..………...………..66

Ivanovic K. ……………..……………..26

Jeong D. ……………..……….………..41

Ji L. ……………..……………………..63

Jiang Z. ……………..……..…………..32



97

Jin X. Y. ……………..……….………..62

Kadowaki K. ……………..24, 26, 34, 36,

37, 59, 79, 84, 87

Kakeya I. ……………..………………..45

Kamrani H. ……………..……………..47

Kangal S. ……………..……...………..88

Kashiwagi T. …………..…..26, 24, 36, 79

Kato R. ………………….……………..48

Katterwe S. O. …………….…………..46

Khan J. A. ……………..…………..…..71

Kim S. J. ……………..…………....80, 81

Kitamura T. ……………….…..24, 26, 79

Kleiner R. ………..………..25, 32, 66, 73

Klemm R. A. …………..24, 26, 36, 42, 79

Klushin A. M. ……………..…………..35

Kobayashi K. …………..…………….. 54

Kocabas K. ……………..……..…..94, 95

Koelle D. …………………..25, 32, 66, 73

Kokabi A. ……………………..47, 77, 91

Kolahchi M. R. ………………..…..55, 78

Koseoglu H. ..59, 84, 85, 86, 87, 90, 91, 93

Koshelets V. P. ..………..……………..38

Koshelev A. E. ………………...34, 56, 57

Koshiya R. …………..…..……………..27

Koval Y. ……………..………………..62

Koyama T. ……………..……...29, 53, 54

Krasnov V. ……………..……….……..46

Kulikov K. …………………….…..55, 82

Kurin V. V. ……………..……………..35

Kurter C. ……………..………………..33

Kusmartsev F. V. ……………..………..38

Kwok W. K. ……………..…………….34

LaBerge E. ……………..……….……..36

Latyshev Y. I. ……………..…………..51

Lee G. H. ……...………..……………..41

Lee H. J. …………….…..……………..41

Li J. ……………..……………..25, 27, 66

Li M. ……………..…..………..32, 66, 73

Lin S. Z. ……………….…………..30, 76

Liu F. ……………..………….………..76

Machida K. ………………..29, 40, 53, 54

Malzer S. ………………..……………..85

Matsumoto H. ……………………..29, 53

Mengyue L. ……………..……………..25

Minami H. …..……………..24, 26, 34, 79

Minematsu M. ……………..…………..84

Miyakawa N. ………...………..77, 84, 91

Miyazawa K. ……………..…..………..48

Mizuta S. ……………..………………..45

Mochiku T. ……………..……………..61

Moftakharzadeh A. ……………..……..77

Mohan R. …………...…..……………..80

Morley D. ……………....……………..36

Motzkau H. ……………..……………..46

Mukaida M. ……………..………...…..81

Müller F. ..……………………………..35

Müller P. ..…………………49, 59, 62, 85

Nakajima K. ……………..……...……..27

Nakayama R. …………..…………….. 79

Ohta Y. ……………..……..…………..54

Oikawa D. ……………..…..…………..65

Okazaki H. ……………...……………..48

Olgar M. A. ………....………….92

Omukai Y. ……………...……………..45

Onbaşlı Ü. ……………….……………..67

Ooi S. ……………..……….…………..61



98

Ota Y. ……………………………..29, 53

Oya G. ……………..…………………..65

Ozaki T. ……………..………….……..48

Özdemir Z. G. ……………..……….…..67

Ozyuzer L. ………………..…………..33,

59, 77, 84, 85, 86, 87, 88, 90, 91, 92, 93

Pedersen N.F. …………...……………..31

Ploss D. ………………………………..85

Preu S . ……………..…………………..85

Probst S. ……………..………….……..62

Proslier T. ……………..……..………..33

Rahmonov I. ……………..………..55, 82

Reid C. ……………….....……………..36

Rizvi S. M. I. ……………..……….…..50

Rydh A. ………………………………..46

Saglam H. ..………..59, 84, 90, 92, 93, 87

Saglam M. …………..……………..43, 75

Saglam Z. ……………..……...………..43

Saini S. ……………..……….……..80, 81

Sakhi S. ……………..……………..69, 83

Saleem S. ……………..……...………..50

Sawamura M. …..……….……..24, 26, 79

Scheller T. …………..…..……………..35

Sekimoto S. ……………..……………..26

Semenov A. D. ……………..……..…..35

Shahabuddin M. ……………..….……..71

Shukrinov Y. ……...…..55, 64, 72, 78, 82

Simsek Y. ……………………..59, 62, 85

Song F. ……………..………...………..35

Stanev V. A. …………………………..56

Steiner C. ……………..………...……..62

Suzuki M. ………...……….45, 55, 74, 78

Tachiki M. ...………..……………..26, 37

Takano Y. ……………....……………..48

Takeya H. ……………....……………..48

Tamura K. ……………..…..…………..65

Tanoglu M. ……………..……………..88

Tsujimoto M. ……………..24, 26, 36, 79

Turkoglu F. ………..…..59, 84, 85, 86, 87

Wakahara T. ……………..…..………..48

Wang H. ……....25, 27, 32, 60, 66, 73, 85

Wang P. …………….…..……………..63

Warburton P. A. ……………...………..50

Ward L. D. ……………...……………..50

Watanabe C. ……………..……..……..26

Watanabe T. ……………..……...……..74

Welp U. ………………....……………..34

Wootton T. A. ………………….……..50

Wu P. ……………...…………..25, 32, 66

Xie W. ……………..…………………..63

Yamada H. ……………...……………..27

Yamaguchi T. ……………..…………..48

Yamaki K. ……………..…..…………..65

Yamamoto T. ………….…..26, 34, 79, 84

Yaman M. D. …………...……..88, 90, 93

Yamashita T. ……………..…….……..44

Yan S. L. ………………..……………..63

Yanmaz E. ……………………..92

Yazici S. …………...…………….. 90, 92

Yuan J. ………….……..25, 27, 32, 66, 73

Zasadzinski J. F. ……………..………..33

Zhang X. …………………..…………..63

Zhao X. J. ……………..…..…………..63

Zhong Y. ……………..………………..32

Documents

SNA+MC 2010 Summary Paper - plasma2012.iyte.edu.tr/docs/abstract book-PLASMA2012.pdf · Oscillations in High-Tc Superconductors (PLASMA 2012)” being held