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schuine kaderlijn 4º

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40th Meeting of the section Atomic Molecular and Optical Physics

Program and abstracts11 and 12 October 2016

Conference center De Werelt Lunteren

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40th Meeting of the section Atomic Molecular and Optical Physics (AMO)

Program and abstracts

Conference center De Werelt Lunteren

October 11 and 12 2016

Scientific Commitee :

Giel Berden • Klaas-Jan van Druten • Kjeld Eikema • Martin van Exter

• Ronald Hanson • Steven Hoekstra • Gert ‘t Hooft • Femius Koenderink

Servaas Kokkelmans • Bas .v.d. Meerakker • Herman Offerhaus (chair)

Dries van Oosten • Paul Planken • Caspar van der Wal

Program Committee : Dries van Oosten • Ronald Hanson

This meeting is organized under the auspices of the NNV-section Atomic, Molecular and Optical

Physics, with financial support of the Dutch Science Foundation and the Foundation FOM.

Conference coordination :

Erna Gouwens (RU)

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Tuesday 11 October 2016

10.00 Arrival, registration10.40 Opening by the chair of the section AMO Herman Offerhaus

chair : Rene Gerritsma 10.45 I 1 Stefan Witte (ARCNL and VU University Amsterdam) “Interferometry, spectroscopy and lensless imaging with extreme-ultraviolet radiation”11.30 Short lectures : (Europa room) O 1 Jeroen Bosch (Debye Institute for Nanomaterials Science EMMEPH, Utrecht University) “Spectral width of open transmission channels” O 2 C. Cheng (LaserLaB, Department of Physics and Astronomy, VU University Amsterdam) “Ammonia molecules up to 266 milliseconds in free fall in a molecular fountain” O 3 S.B. van Dam (QuTech, Delft University of Technology) “An efficient quantum spin-photon interface in diamond for a quantum network” O 4 Zhi Gao (Molecular and Laser Physics, IMM, Radboud University Nijmegen) “Product-pair correlations in NO-O2 inelastic collisions”

12.30 Lunch

chair : Steven Hoekstra14.00 I 2 Alfred Leitenstorfer (University of Konstanz, Konstanz, Germany) “Time-domain quantum optics”

14.45 Short lectures : (Europa room) O 5 J.O. Grasdijk (Van Swinderen Institute, University of Groningen) “Search for the permanent electric dipole moment of xenon”

O 6 S. Greveling (Debye Institute for NanoMaterials Science and EMMEPH, Utrecht University) “Density distribution of a Bose-Einstein condensate of light in a dye-filled microcavity”

Tuesday 11 October 2016

15.15 Coffee/tea break (attach posters) 15.45 Short lectures: (Europa room)

O 7 J. Joger (Institute of Physics, University of Amsterdam) “Setup for studying Li-Yb+ mixtures in the quantum regime” O 8 L. Liao (Debye Institute for Nanomaterials, Utrecht) “Faraday excitations in a Bose-Einstein condensate” O 9 G.J.J. Lof (Zernike Institute for Advanced Materials, University of Groningen) “Proposal for time-resolved optical probing of triplet-exciton spin dynamics in organic molecules” O 10 R.P.M.J.W. Notermans (LaserLaB, VU University, Amsterdam) “Quantum statistics in the spectral line shapes of quantum degenerate metastable 4He and 3He” 16.45 Poster presentations (odd numbers) 18.00 Dinner (restaurant) 19.15 Poster presentations (even numbers)

chair: Paul Planken21.15 I 3 Prof. Habakuk (Rene Beigang) (University of Kaiserslautern, Germany) “The illusion of the laws of nature: Science beyond causality”

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Wednesday 12 October 2016

08.00 Breakfast (restaurant, please remove the luggage from your room)10.40 Opening by the chair of the section AMO Herman Offerhaus

chair : Willmann 08.45 I 4 Stefan Willitsch (University of Basel, Switzerland) “Ion-atom and ion-molecule hybrid systems: new avenues for studying cold ion-neutral interactions”

09.30 Short talks (Europa room) O 11 Marcin Plodzien (Eindhoven University of Technology) ‘Rydberg dressing in a Bose-Einstein condensate” O 12 Mohammad Ramezani (Dutch Institute for Fundamental Energy Research (DIFFER) Eindhoven University of Technology) “Plasmon-exciton-polariton lasing” O 13 Roy Scheidsbach (Molecular and Laser Physics, IMM, Radboud University Nijmegen) “Imaging astrochemistry“ O 14 Maarten Soudijn (Institute of Physics - University of Amsterdam) “Coherent manipulation of atomic ensembles trapped in a magnetic lattice on a chip”

10.30 Coffee/tea break

chair : Sanli Faez11.00 I 5 Matthias Weidemuller (University of Heidelberg, Germany) “Rydberg atom – Light interfaces”

11.45 Short lectures : (Europa room) O 15 Tristan Tentrup (MESA+ Institute for Nanotechnology, University of Twente) “Increasing the information content of single photons” “Search for the permanent electric dipole moment of xenon”

O 16 F. Torretti (ARCNL, Amsterdam) “Analysis of the fine structure of Sn7+…14+”

O 17 Michele Cotrofu (COBRA Research Institute, Eindhoven University of Technology) “Optically-controlled coherent atom-phonon interaction in optomechanical systems” O 18 Wouter Verhoeven (Coherence & Quantum Technology Group, Eindhoven University of Technology) “Time-resolved electron microscopy”

12.45 Lunch

chair : Herman Offerhaus13.55 Presentation winner poster award

chair : O 19 Artem Zapara (Van Swinderen Institute, University of Groningen) “Traveling-wave Stark decelerator: the slowest beam of SrF” O 20 Hugo Doeleman (FOM Institute AMOLF, Amsterdam) “Better together: Purcell enhancement at any linewidth in antenna-cavity hybrids” 14.30 I 6 Mike Tarbutt (Imperial College Londen, United Kingdom) “Laser cooling and magneto-optical trapping of molecules: experiments and models” 15.20 Finish

Wednesday 12 October 2016

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Lasers have given researchers the ability to produce bright coherent beams of light. Having a coherent light source enables a wealth of experiments that provide access to the phase of the light waves rather than just the intensity. High-harmonic generation (HHG) is a process that enables the production of fully coherent pulses of extreme-ultraviolet (EUV) and soft-X-ray radiation using compact high-intensity lasers. The short-wave-lengths and associated high photon energies of EUV radiation give rise to very different light-matter interaction compared to visible light: EUV radiation can penetrate optically opaque materials, but can also be used to probe inner-shell electrons in atoms and molecules.

The ability to perform interferometry with HHG sources would enable the translation of powerful optical methods such as Fourier transform spectroscopy and coherent imaging to the EUV spectral range. However, due to the short wavelengths involved, the extreme stability requirements and optical components pose a challenge. I will explain our approach to ultra-stable interferometry with HHG sources, and discuss various experi-ments that we have performed using coherent EUV radiation.

Schematic principle of Fourier transform diffractive imaging. A pair of coherent EUV pulses is incident on a sample, and a sequence of images is recorded as a function of time delay T. Fourier transformation of the measured data along the time axis provides spectrally resolved coherent diffraction patterns, which can be used to retrieve an image of the object.

Interferometry, spectroscopy and lensless imaging with extreme-ultraviolet radiation

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Stefan WitteARCNL and VU University

Amsterdam

Jeroen Bosch1,2, Sebastianus A. Goorden2,3, and Allard P. Mosk1,2 1 MESA+ Institute for Nanotechnology, Universiteit Twente 2 Debye Institute for Nanoma-terials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University 3 Present adress: ASML Netherlands B.V., Veldhoven

Open transmission channels allow unity transmission through arbitrarily thick non-absorbing diffusive materials. Wavefront shaping allows coupling of light to open transmission channels.

We report measurements of the spectral width of open transmission channels in three-dimensional diffusive media. By repeated digital optical phase conju-gation light is efficiently coupled to open transmission channels, thereby increasing the transmission through a sample. After coupling light to open transmission chan-nels we vary the wavelength of the incident light while fixing the spatial field profile. For every wavelength the transmitted field and transmitted power is measured.

We find that the enhancement of the trans-mission has a full width at half maximum with approximately twice the width of the speckle correlation function C1 (ω), indi-cating that the spectral width of an open transmission channel is larger than that of the transmission channel average.

C. Cheng, A.P.P. van der Poel, W. Ubachs, and H.L. Bethlem LaserLaB, Department of Physics and Astronomy, VU University Amsterdam

Ultimately, the resolution of any spec-troscopic experiment is limited by the coherent interaction time between the light field and the particle that is being studied. The introduction of cooling techniques for atoms and ions has resulted in a dramatic increase of interaction times and accuracy, it is hoped that molecular cooling tech-niques will lead to a similar increase. We present experiments on a molecular fountain which enables the study of mole-cules in free fall for up to 266 milliseconds. In our experiment, beams of ammonia molecules are decelerated, trapped and cooled using electric fields and subse-quently launched. Using a combination of quadrupole lenses and buncher elements, the beam is shaped to have a large position spread and a small velocity spread while the molecules are in free fall, but strongly focused at the detection region. Our work make sub-Hz measurements in molecular systems possible, which paves the way for stringent tests of fundamental physics theories in molecules.

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Spectral width of open transmission channels

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Ammonia molecules up to 266 milliseconds in free fall in a molecular fountain

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S.B. van Dam1, S. Bogdanovic1, C. Bonato1, B. Hensen1, M. S. Z. Liddy2, L.C. Coenen1, A. Reiserer1, M. Lonçar3, and R. Hanson1 1QuTech, Delft University of Technology2IQC, University of Waterloo3Harvard University

In a future quantum network distant parties will be connected via long-distance entan-glement. Nitrogen-vacancy (NV) centers in diamond have developed into a building block for such a network. The current success probability of heralded entangle-ment generation over 1.3 km is about 10-8 [1], limited by the probability that the NV center emits a photon in the zero-phonon line, as well as by the photon collection efficiency from the diamond. We can address both by embedding the NV in a Fabry-Perot cavity at cryogenic temper-atures, benefitting from Purcell enhance-ment and an improved collection efficien-cy. We report work on such a system with an NV in a diamond membrane in a tunable fiber-based microcavity. This new quan-tum interface should enable a significant speed-up in the remote entangling rate, and allow us to extend a quantum network over multiple nodes and longer distance.

[1] Nature 526, 682 (2015).

Zhi Gao, Sjoerd N. Vogels, Tijs Karman, Matthieu Besemer, Gerrit C. Groenenboom,Ad van der Avoird, and Sebastiaan Y. T. van de Meerakker Molecular and Laser Physics, IMM, Radboud University Nijmegen

In molecule-molecule inelastic collisions, both molecules may undergo a change of rotational quantum state. The measurement of product pair correlations reveals the state-to-state cross sections for both molecules in coincidence, which is an essential ingredient to unravel the scatter-ing dynamics. Measurements of product pair correlations have been proven extremely challenging, and experimental data is thus far lacking.

The combination of the Stark deceleration and velocity map imaging techniques allow for studies of atom-molecule collisions at very high resolution. Recently we extended this technique to molecule-molecule colli-sions, revealing product pair correlations for inelastic collisions between NO and O2 molecules.

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An efficient quantum spin- photon interface in diamond for a quantum network

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Product-pair correlations in NO-O2 inelastic collisions

Product pair correlations for NO-O2 inelastic collisions. The multiple rings correspond to rotational excitations that occur in coincidence in both molecules.

Alfred LeitenstorferUniversity of Konstanz,

Konstanz, Germany

Extremely broadband electro-optic sampling with few-femtosecond and highly stable laser pulses has recently enabled us to directly detect the vacuum fluctuations in the ground state of the electric field [1,2]. The effective noise amplitude ∆E depends on the four-dimensional space-time volume over which a measurement process or a physical system integrates (see figure). Recently, we were able to generate time-locked squeezed transients in the mid infrared with local fluctuation amplitudes substantially below the vacuum level [3]. Our new approach to quantum electrodynamics is based on a time resolution better than the oscillation cycle of the radiation field. This fact provides access to the ground-state properties without amplification to finite intensity. The time-domain view on spontaneous emission of highly correlated photon fields identifies them as an immediate consequence of the uncertainty principle in combination with accelerations and retardations of the local reference frame.

Alfred Leitenstorfer is Professor of Experimental Physics and chairs the Center for Applied Photonics at University of Konstanz. Following the completion of his PhD at Technical University of Munich in 1996, he worked as a postdoctoral member of the technical staff at Bell Laboratories, Lucent Technologies in Holmdel, NJ. After his habil-itation in 2000 and an intermediate position as a Professor for Optoelectronics at LMU Munich, he moved to Konstanz in 2003. Leitenstorfer’s research focusses on ultrafast phenomena in condensed-matter and quantum physics, supported by research on advanced femtosecond and terahertz technologies. He has received the Rudolf Kaiser Prize, the Arnold Sommerfeld Award and the Rudolf Genzel Prize. Leitenstorfer is a Fellow of the Optical Society and holds an Advanced Grant of the European Research Council.

References:[1] C. Riek et al., Science 350, 420 (2015)[2] A. S. Moskalenko et al., Phys. Rev. Lett. 115, 263601 (2015)[3] C. Riek et al., CLEO 2016, postdeadline paper JTh4A.6

Time-domain quantum opticsI 2

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Illustration of spatiotemporal sampling of the quantum vacuum electric field (color-coded red and blue in one plane). The average fluctuation amplitude ∆E follows from the effective cross section ∆x∆y of the transverse mode (pink) and the two-dimensional length-duration ∆z∆t of a femtosecond probe pulse (green) in the electro-optic detector crystal.

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F. Allmendinger2, P. Blümler1, M. Doll1, J.O. Grasdijk3,1, W. Heil1, K. Jungmann3, S. Karpuk1, H.-J. Krause4, A. Offenhäusser4, M. Repetto1, U. Schmidt2, Y. Sobolev1, L. Willmann3, S. Zimmer1 1University of Mainz, 2University of Heidelberg, 3VSI, University of Groningen, 4Research Center Jülich

A permanent electric dipole moment (EDM) implies breakdown of P (parity) and T (time reversal) symmetries. Provided CPT holds, this implies CP violation. Observation of an EDM at achievable experimental sensitivity would provide unambiguous evidence for physics beyond the Standard Model and limits towards matter-antimatter asymmetry. In an ongoing measurement we aim towards some 10 times improvement over the current limit on any EDM (|dHg| < 7.4x10-30 e cm at 95% C.L. [1]).

Using a spin clock [2] with co-located spin polarized 3He and 129Xe and SQUID detec-tors to monitor free spin precession of both species simultaneously an EDM sensitivity of ~10-30 e cm is possible. A first test run will be reported.

[1] B. Graner et al., PRL 116, 161601 (2016)

[2] C. Gemmel et al., Eur. Phys. J D 47, 303 (2010)

S. Greveling, K. Perrier, and D. van OostenDebye Institute for NanoMaterials Science and EMMEPH, Utrecht University

In 2015 we became the third group in the world to achieve Bose-Einstein condensa-tion of photons using a dye-filled micro-cavity. When increasing the photon density inside our system we observe an increase in the size of our condensate, indicating that there are effective photon-photon interactions. The group of Martin Weitz attribute these to thermal effects[1]; local heating of the dye solvent leads to a local change in the refractive index, which in turn leads to a change in the trapping potential experienced by the photon gas. However, the source of the heating as well as the timescale of the resulting interac-tions are largely not understood. We will discuss our experimental results and their relation to the interaction mechanism.

[1] J. Klaers, et al., “Bose-Einstein condensation of

paraxial light”, Applied Physics B 105, 17-33 (2011)

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Search for the permanent electric dipole moment of xenon

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Density distribution of a Bose-Einstein condensate of light in a dye-filled microcavity

Low photon density High photon density

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J. Joger, H. Fürst, N. Ewald, T. Secker,

and R. Gerritsma Institute of Physics, University of Amsterdam

Mixtures of atoms and ions form excit-ing new systems in which to directly investigate quantum chemistry, ultra-cold collisions and polaronic physics. Possible applications include sympathetic cooling of ions, ion-assisted detection of atoms and quantum simulation. I will present our setup for realising a hybrid system of ultra-cold Li atoms and Yb+ ions which we are currently characterising. The large mass-ratio between the atom and ion will allow us to reach the ultracold regime for ions trapped in a Paul trap. In this regime, the quantum dynamics of mixtures of fermionic atoms and ions and of fermion- phonon coupling may be studied [1].

[1] U. Bissbort et al., Phys. Rev. Lett. 111, 080501 (2013).

[2] C. Gemmel et al., Eur. Phys. J D 47, 303 (2010)

L. Liao2, A. Groot1, J. Smits1, P.C. Bons1, H.T.C. Stoof2, and P. van der Straten1 1Debye Institute for Nanomaterials, Utrecht, The Netherlands2Institute for Theoretical Physics, Utrecht, The Netherlands

Parametric excitations of a Bose-Einstein condensate can be induced by modulating the radial trap frequency of the trap. By shortly pulsing the radial trap frequency we induce quadrupole oscillations of the cloud in both directions and after some time we observe the emergence of a Faraday pattern. The period of the Faraday pattern depends strongly on the aspect ratio of the trap, as can be seen in Fig. 1. The dynamics of the Faraday pattern is studied using phase-contrast imaging. We investi-gate theoretically the interplay between the Faraday mode and the radial quadrupole mode of the condensate. In the model we want to establish the condition for which the Faraday pattern occurs.

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Setup for studying Li-Yb+ mixtures in the quantum regime

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Faraday excitations in a Bose-Einstein condensate

Figure: Yb+ ion crystal in our ion trap.

Figure 1. In-situ images of a Bose-Einstein condensate containing Faraday patterns. By changing the radial trap frequency, as shown in the upper left corner of the images, the pattern can be observed

for different aspect ratios of the trap.

G.J.J. Lof 12, X. Gui2, R.W.A. Havenith2,3,4, and C.H. van der Wal1 1Physics of Nanodevices group; 2Theoretical Chemistry; Zernike Institute for Advanced Materials, University of Groningen, 3Stratingh Institute for Chemistry, University of Groningen, 4Ghent Quantum Chemistry Group; Department of Inorganic and Physical Chemis-try, Ghent University, Belgium

Due to their chemical tunability, low-cost and ease of processing, organic molecules are often used for opto-electronic devices, where the ratio of singlet to triplet excitons can be an important performance parameter. A better understanding of the correlation between the exciton spin states and the polarization of optical transitions will contribute to this field, as well as to the field of spintronics. This theoretical work proposes an experimental technique that can harness this correlation. The Time-Resolved Faraday Rotation technique allows for read-out of triplet-exciton spin dynamics as a function of the delay time between an ultrashort pump and probe pulse. We propose to use a pump pulse to excite to a superposition of triplet sublevels, thereby ini-tiating an oscillation of the expectation value of the total electronic angular momentum as a function of time. To calculate this, we have extended existing theoretical chemistry tools. Experimentally, a suitable measure for such spin precession is the polarization rotation of a linear probe as a function of the delay time between pump and probe.

R.P.M.J.W. Notermans, R.J. Rengelink, and W. VassenLaserLaB, Vrije Universiteit, Amsterdam

With a narrow (linewidth <5 kHz) laser, transfer-locked to an ultrastable laser (linewidth <2 Hz), we are able to excite the doubly forbidden 23S-21S transition at 1557 nm (natural linewidth 8 Hz) in both quan-tum degenerate fermionic 3He and bosonic 4He, trapped in an optical dipole trap. For the first time we resolved the spectral line shapes with such high resolution to observe differences caused by the different quantum statistics of bosons and fermions. We extended the line shape model for an atomic hydrogen BEC in a magnetic trap by including the spatial dependent ac Stark shift of the dipole trap and time-dependent depletion of the condensate. This mod-el agrees well with our data and allows for the first measurement of the 23S-21S s-wave scattering length. This work is an important step towards an improved measurement of the transition frequency in 3He and 4He for a nuclear charge radius difference determination at the 0.5 attom-eter accuracy level, important for solving the proton radius puzzle.

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Proposal for time-resolved optical probing of triplet-exciton spin dynamics in organic molecules

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Quantum statistics in the spec-tral line shapes of quantum dege-nerate metastable 4He and 3He

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“Good Science is like Magic.” This is, in principle, the third law of Arthur C. Clark, a famous science fiction writer (e.g. “Odyssee 2001”) who said that advanced high technology or modern science can hardly be distinguished from magic (A.C. Clark in “Profiles of the future”, 1962). He postulated this law already more than 50 years ago and it is becoming more and more important. These days it is almost impossible for most people to understand the underlying technology of many modern technological gadgets. As a consequence, they simply consider it to be a kind of magic although knowing that it is “just” advanced technology. On the other very hand magicians are very often using scientific results to improve their performance and sell technology as magic tricks being aware that most people don’t know the technology used to perform the illusion.

The border between illusion and reality is sometimes difficult to find. In an unusual lecture about space, time and light this border will be crossed in both directions. The spectator has to find out by himself where science ends and magic and illusions start. He will learn about new and old phenomena in physics, biology and mathematics in a somewhat different way. There is always a direct link to daily life experience, like the well- known “Ladies’ Handbag Phenomenon”. At the end of the lecture the spectator may not have understood everything; however, he should have learned that good science is like magic and more than that: it is a lot of fun.

The Illusion of the Laws of Nature: Science Beyond Causality

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Prof. HabakukUniversity of Kaiserslautern,

Germany

Prof. Habakuk Stefan WillitschDepartment of Chemistry, University

of Basel, Switzlerland

The recent development of experiments for the combined trapping of cold ions and cold neutral atoms has paved the way for studying interactions between these species at extremely low energies. Cold ion-atom hybrid systems were found to display a rich collisional and chemical dynamics including sympathetic cooling of ions by atoms, charge exchange and the formation of molecules by radiative association [1]. In the talk, we focus on new developments in the realm of ion-neutral hybrid experiments. First, we present a new type of hybrid trap which enables cold ion-atom collision experiments with a greatly improved energy resolution on the scale of a few mK. The experiment consists of strings of cold, localized ions sandwiched in between two magneto-optical traps (MOT). Using radiation-pressure forces, cold atoms are shuttled back and forth between the MOTs passing through the ion crystal with a well-defined con-trollable energy (see figure). Second, we present progress towards the extension of hybrid trapping technology to molecular systems by combining cold molecular ions with cold neutral molecules. Third, we highlight first steps towards the miniaturization of ion-atom hybrid experiments by combining an atom chip with an ion chip.

References:[1] A. Härter, J. Hecker Denschlag, Contemp. Phys. 55, 33 (2014); S. Willitsch, Int. Rev. Phys. Chem. 31, 175 (2012); S. Willitsch, Proc. Int. Sch. Phys. Enrico Fermi 189, 255 (2015); C. Sias and M. Köhl, p.267 in Quantum Gas Experiments, ed. P. Törmä and K. Sengstock, World Scientific 2014.

Stefan Willitsch received his PhD from ETH Zurich in 2004. From 2004-2007, he was a Junior Research Fellow at the University of Oxford. In 2007, he was appointed Lecturer at University College London and in 2008 Professor in Physical Chemistry at the University of Basel.

Ion-atom and ion-molecule hybrid systems: new avenues for studying cold ion-neutral interactions

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Marcin Płodzień 1, Servaas Kokkelmans1, Graham Lochead2, N. J. van Druten 1Eindhoven University of Technology, Eindhoven, Netherlands2University of Amsterdam, Amsterdam, Netherlands

We study the influence of Rydberg dressed interactions in a one-dimensional Bose-Einstein Condensate. These Rydberg-dressed atoms can serve as a quantum simulator, for instance to study energy transport in biological systems. The effects of dressing are studied by investigating collective BEC dynamics after a rapid switch-off of the Rydberg dressing interaction. The results can be interpreted as an effective modification of the s-wave scattering length.

Mohammad Ramezani1, Alexei Halpin1, Johannes Feist2, Antonio Fernán-dez-Domínguez2, Said Rahimzadeh-Kalaleh Rodriguez3, Francisco J. Garcia-Vidal2,4 and Jaime Gómez-Rivas1,5

1- Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ, Eindhoven, The Netherlands2- Departmento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain3- Laboratoire de Photonique et Nanostructures, LPN/CNRS, Route de Nozay, 91460 Marcoussis, France4- Donostia International Physics Center (DIPC), E-20018 Donostia/San Sebastian, Spain5- COBRA Research Institute, Eindhoven Uni-versity of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands

Strong light-matter interaction leads to the appearance of new states, i.e. exciton-po-laritons, with photophysical properties rather distinct from their constituents. Recent developments in fabrication tech-niques allow us to make metallic structures with strong electric field confinement in nanoscale mode volumes, allowing for fac-ile assembly of strongly coupled systems at room temperature based on a hybrid organic-plasmonic architecture. In this research, a planar array of metallic

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Rydberg dressing in a Bose-Einstein condensate

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Plasmon-exciton- polariton lasing

nano-antennas is covered by a polymer layer doped with organic molecules, where we use photoluminescence spectroscopy to measure an onset in nonlinear emission. At increasing doping levels we observe an enlargement of the Rabi splitting caused by strong coupling and concomitant decrease in lasing threshold, this in spite of a strong reduction in photoluminescence lifetime and quantum yield for the dye. Moreover, using angular resolved photoluminescence we record the thermalization of polari-tons in the nonlinear regime, into a mode which is dark in the linear regime. These measurements point towards signatures of stimulated scattering of plasmon-exci-ton-polaritons at room temperature in an open cavity.

Roy Scheidsbach and David Parkerand Molecular and Laser Physics, IMM, Radboud University Nijmegen

Molecular oxygen, O2, is a fascinating molecule involved in many processes occurring on Earth and the interstellar medium (ISM). Cold gases, which are observed in regions of the ISM where thermal desorption is negligible, may arise from photo-desorption from icy grains, especially in regions with high UV flux. In this study we carry out velocity map imaging (VMI) experiments on ultraviolet photo-desorption of O2 molecules and O atoms from an O2-ice surface at 10K. The information we obtain should give more insight into similar processes taking place at icy interstellar grains. We have recently completed our “ice-machine” apparatus which combines the Velocity Map Imaging technique with an ultra-high vacuum ice surface setup with controlled doping and surface analysis by thermal programmed desorption. First results were achieved in March 2016. Using state selec-tive ionization of desorbed molecules by REMPI and full 3-D velocity information from the imaging technique it is possible to gain more detailed insight into the processes occurring on ice surfaces.

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Imaging astrochemistry

--> We acknowledge support by the NWO-CW TOP project 715.013.002 and collaboration with H. Linnartz (Leiden) and H. Cuppen (RU).

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Maarten L. Soudijn, S. Machluf, C. Sanna, A.L. La Rooij, J.B. Naber, D. Davtyan, N.J. van Druten, H.B. van Linden van den Heuvell, and R.J.C. SpreeuwInstitute of Physics - University of Amsterdam

Using a permanent magnetic-film atom chip we load clouds of tens of 87Rb atoms (~ 2 μK) in a lattice of microtraps with a lattice spacing of 10 m [1]. In these ensembles we measure coherence times of superpositions between our prospective qubit states: magnetically trapped hyper-fine states. We measure near ‘magic field’ conditions where they become ‘clock states’ with potentially long co-herence times. We investigate individual microtrap properties like bottom field, trapping frequencies, lifetime and temper-ature. Evaluating inhomogeneities of e.g. the bottom field we find variations of ~5% across the chip. However, the variation of coherence time between traps is much larger and found to be strongly correlated with number of atoms. Therefore we inves-tigate the role of spin-changing collisions on the lifetime in the microtraps and on the coherence time.

[1] Rev. Sci. Instrum. 85, 053102 (2014)

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Coherent manipulation of atomic ensembles trapped in a magnetic lattice on a chip

Matthias WeidemüllerCenter for Quantum Dynamics, University

of Heidelberg, Germany

Interfacing light and matter at the quantum level is at the heart of modern atomic and optical physics and enables new quantum technologies involving the manipulation of single photons and atoms. A prototypical atom-light interface is electromagnetically induced transparency, in which quantum interference gives rise to hybrid states of photons and atoms called dark-state polaritons. Rydberg gases represent an ideal system to explore the interplay between coherent light excitation and dipolar interatomic interactions. I will review recent advances in the field with special emphasis on work performed in my group in Heidelberg [1-7].

References:[1] M. Robert-de-Saint-Vincent et al., Phys. Rev. Lett. 110, 045004 (2013).[2] H. Schempp et al., Phys. Rev. Lett. 112, 013002 (2014).[3] C. S. Hofmann et al., Phys. Rev. Lett. 110, 203601 (2013).[4] G. Günter et al., Phys. Rev. Lett. 108, 013002 (2012).[5] G. Günter et al., Science 342, 954 (2013).[6] H. Schempp et al. Phys. Rev. Lett. 115, 093002 (2015).[7] V. Gavryusev et al., J. Phys. B 49, 164002 (2016).

Rydberg atom – Light interfacesI 5

1 Physics Institute and Heidelberg Center for Quantum Dynamics, University of Heidelberg, Germany2 Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, and CAS

Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University

of Science and Technology of China, Hefei, China.

E-mail: weidemueller@uni-heidelberg.de

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Tristan B.H. Tentrup, Thomas Hummel, Allard P. Mosk, and Pepijn W.H. PinkseMESA+ Institute for Nanotechnology, University of Twente

A common way to encode information in single photons is the use of polarization, which allows a maximum of 1 bit per photon. Encoding in a higher-dimensional Hilbert space allows to transfer more infor-mation per photon. We use a spatial light modulator (SLM) to control the spatial position of single photons generated by a spontaneous parametric down-conversion source. We experimentally demonstrate selective addressing of any position (sym-bol) in a grid (alphabet) of 36126 symbols, achieving 12.1 bit of mutual information between the sender and receiver per detected photon. Our results set the stage for very-high-dimensional Quantum Key Distribution (QKD), where the increase of information per photon not only increases the possible key generation rate but also the security of the protocol.

F. Torretti1,2 A. Windberger1,3 , A. Borschevsky4 , A. Ryabtsev5 , S. Dobrodey3, H. Bekker3, W. Ubachs1,2 , R. Hoekstra1,4 , J. R. Crespo López-Urrutia3 and O. O. Versolato1

1 ARCNL, Amsterdam2 Vrije Universiteit, Amsterdam3 Max Planck Institute for Nuclear Physics, Heidelberg4 University of Groningen, Groningen5 ISAN and EUV Labs, Moscow

Due to the complex electronic configura-tions of highly charged Sn7+…14+ with open 4d subshells, spectroscopic line identifi-cations and level assignments represent a challenge for both theory and experiment. Despite the technological importance of these ions, used in laser-produced-plas-ma sources for nanolithography, only few studies have been dedicated to level identifications. We provide new charge-state-resolved spectral data in the optical range using an electron beam ion trap. We identified transitions in the lowest configurations of Sn7+…14+ using ab initio Fock space coupled cluster calculations as well as semi-empirical calculations within the Cowan code framework. Our experi-mental and theoretical results indicate that previous identifications in these ions need to be revisited [1].

[1] A. Windberger et al, accepted, Phys. Rev. A, 2016

O 15

Increasing the information content of single photons

O 16

Analysis of the fine structure of Sn7+…14+

Michele Cotrufo1, Andrea Fiore1 and Ewold Verhagen2 1COBRA Research Institute, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands2Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands

We propose and theoretically investigate a new class of hybrid optomechanical systems that provide a coherent interaction between an emitter and a mechanical oscillator, mediated by the field of an optical cavity. The interaction arises from the mechanically-induced modification of the spatial distribution of the optical vacuum field (as sketched in fig. a), which in turn modulates the atom-photon coupling rate. The strength of the inter-action can be controlled by varying the intensity of the optical field, thus opening the way to optically-controlled coherent manipulation of the emitter-phonon system. We discuss realistic designs and possible applications including emitter- phonon swapping (fig. b), which are feasible with experimentally available parameters.

Wouter Verhoeven1, Jasper van Rens1, Erik Kieft2, Peter Mutsaers1, and Jom Luiten1 1Coherence & Quantum Technology Group, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands2FEI Company, Acht, 5651 GG Eindhoven, Netherlands

In collaboration with FEI Company, we are studying the possibility of using a micro-wave TM110 ‘streak’ cavity in combination with a slit to chop a continuous electron beam into 100 fs electron pulses. We have shown that this can be done with minimal increase in transverse emittance and longi-tudinal energy spread. Accurately synchro-nized to a mode-locked laser system, this allows for pump-probe experiments with the spatial resolution of high-end electron microscopes.At the Eindhoven University of Technol-ogy, such a cavity has been implemented in a 200 keV FEI Tecnai microscope. With this setup, a temporal resolution of several picoseconds can currently be achieved without loss of beam quality.Furthermore, an ultrafast 30 keV SEM is operational for spectroscopic purposes. One experiment that has been performed is a time-of-flight measurement, allowing for femtosecond electron energy spectroscopy. Furthermore, we are using this setup to in-vestigate the interaction between electrons and light.

O 17

Optically-controlled coherent atom-phonon interaction in optomechanical systems

O 18

Time-resolved electron microscopy

24 25

Artem Zapara, Kevin Esajas, Sreekanth Mathavan, and Steven HoekstraVan Swinderen Institute, University of Groningen

Deceleration and trapping experiments with heavy diatomic molecules are of great interest since they pave the way towards high-precision molecular spectroscopy and the exploration of physics beyond the Standard Model. The precision of such experiments is limited by the intrinsic sen-sitivity of the molecule of choice, number of molecules and the interrogation time. To increase the interrogation time we reduce the forward velocity of a molecular beam by means of time-dependent electric fields in a traveling-wave Stark decelerator. We present new experimental results of the deceleration of SrF, a molecule that is particularly sensitive to parity violation. We recently achieved the deceleration from 290 to 120 m/s that corresponds to removal of ~85% of the initial kinetic energy. This beam is already slower than buffer-gas cooled beams and is an exciting starting point for novel precision experiments.

Hugo Doeleman, Ewold Verhagen and Femius KoenderinkFOM Institute AMOLF, Amsterdam

Strong interaction between light and a single quantum emitter is pivotal to many applications, including single photon sources and quantum information pro-cessing. Typically, plasmonic antennas or optical cavities are used to boost this interaction. The former can focus light in a deeply subwavelength region, whereas the latter can store light for up to billions of oscillations. We show theoretically that hybrid cavi-ty-antenna systems can achieve Purcell enhancements far exceeding those of the bare cavity and antenna, and can do so at any desired bandwidth. This is a highly nontrivial result: one has to balance in how far the antenna spoils the cavity and vice versa against cooperative and interfer-ence effects. Moreover, these systems can efficiently couple the generated light into a single-mode output channel, avoiding the losses usually associated with plasmonics. Finally, we show first experimental results on hybrid systems using a whispering-gal-lery mode cavity and a plasmonic antenna.

O 19

Traveling-wave Stark decelera-tor: the slowest beam of SrF

O 20

Better together: Purcell enhancement at any linewidth in antenna-cavity hybrids

Mike Tarbutt1Centre for Cold Matter, Blackett

Laboratory, Imperial College London, UK

Ultracold molecules produced by direct laser cooling can be used for applications in particle physics, quantum simulation and quantum chemistry. We slow and cool a beam of CaF molecules to low velocity using frequency-chirped or frequency-broadened coun-ter-propagating laser light. The velocity of the beam can be reduced to a few m/s, while compressing its velocity spread by a factor of ten and retaining its high brightness. The slow molecules are delivered to a magneto-optical trap (MOT) where we aim to cool them to µK temperatures.

To advance our understanding of how molecules are cooled and trapped in a 3D MOT, we use multi-level rate equations and optical Bloch equations. The molecules are pumped into dark Zeeman sub-levels, which weakens the cooling and trapping forces, and the force is further weakened when the excited state has a small magnetic moment. Both effects are avoided when the MOT beams contain two oppositely-polarized laser components, one red- and one blue-detuned. We find that sub-Doppler processes are also important in the molecule MOT. When the light is red-detuned, the temperature is raised by sub-Doppler mechanisms which oppose the Doppler cooling force at low velocities. The temperature can be lowered by lowering the light intensity, and by switching to a blue-detuned molasses or MOT.

Laser cooling and magneto-optical trapping of molecules: experiments and models

I 6

26 27

NOTES

PostersConference center

De Werelt Lunteren

28 29

Nico R. Verhart, Subhasis Adhikari, Amin Moradi, and Michel OrritLeiden Institute of Physics, Leiden University

The fluorescence from a single organic dye molecule can in principle be switched on and off by pumping the molecule to a long-lived triplet state T1 [1]. This requires the transition energy between the singlet ground state S0 and the triplet state T1 to be known. Here, we attempt to locate the S1 and T1 states of perylene dye molecules in a solid matrix of ortho-dichlorobenzene (o-DCB) and a naphthalene host matrix via bulk fluorescence and phosphorescence spectroscopy, respectively at a cryogenic temperature (~ 1.2 K). In addition, we attempt to locate the T1 states via S0 --> T1 absorption using a lock-in technique.

Reference:

1. M Orrit, Nature (2009), 460, 42 - 44

R.K. Altmann, L.S. Dreissen, S. Galtier and K.S.E. EikemaLaserLaB, VU University, Amsterdam

High-resolution spectroscopy of sim-ple atoms and molecules can be used to determine fundamental properties of matter such as the proton-charge radius. However, spectroscopy of electronic- and muonic-hydrogen give wildly different radii, which cannot be explained by theory. An interesting system to further investigate this conundrum is molecular hydrogen, due to recent advances in calculation of the energy levels. Spectroscopy of singly-ion-ized helium is likewise interesting, but also challenging because deep-ultraviolet or extreme-ultraviolet radiation is required to excite ground-state electronic transitions. To overcome this challenge we have devel-oped “Ramsey-comb” spectroscopy, based on pairs of amplified frequency-comb puls-es that can be used for efficient frequency upconversion in non-linear processes. We present here our latest result on the EF<--X two-photon transition in H2 at 2×202 nm, with a preliminary 15 kHz statistical uncertainty.

P 1

The location of the T1 triplet state of perylene in a solid matrix

P 2

High-precision deep-UV spectroscopy in H2

-->

Dashdeleg Baasanjav1, Sela Samin2, Allard P. Mosk1, and Sanli Faez1 1 Debye Institute for Nanomaterials Science, Utrecht University2 Institute for Theoretical Physics, Utrecht University

We present numerical modelling of a new optofluidic platform (figure) for measuring the electrophoretic mobility of charged single nanoparticles moving inside a closed nanocapillary under external fields [1, 2].

We calculated the time dependence of the axial velocity of fluid and electric field inside capillary for various salt concen-trations and found similar behaviour to that observed in the experiment. Bulk fluid velocity decays non-exponentially when applied voltages at the electrodes is reversed in step-like fashion. Axial electric field along the pore is also shown to be uniform both axially and radially thus further demonstrating underlying electroki-netic dynamics inside the nanocapillary.

[1] S. Faez et al., ACS Nano, 2015, 9 (12), 12349

[2] S. Faez et al., Faraday Discuss., 2016,

DOI: 10.1039/C6FD00097E

J.L.P. Barreaux1, S I.V. Kozhevnikov2, M. Bayraktar1, R.W.E. van de Kruijs1, H.M.J. Bastiaens1, F. Bijkerk1, and K.-J. Boller1 1. University of Twente, 2. Shubnikov Institute of Crystallography (RAS)

As extreme ultraviolet (EUV) lithography is developed further, simplified instru-mentation for monitoring and comparing the output of available EUV sources is required. These sources can generate powerful radiation in the 13.5 nm band, but they emit also a significant amount of out-of-band radiation, hence requiring spectral filtering with sufficient resolution to determine the amount of in-band radi-ation power. Next to reflective multilayer mirrors or diffractive spectrometers, realizing narrowband filters that work in transmission, is of particular interest due to the option of providing highly compact devices for spectral monitoring. Here we present the first experimental demonstration of anomalous transmission filters. Using a stack of Ni/Si multilayers we provide a high transmission-to-bandwidth ratio for a wavelength of 13.5 nm and at normal inci-dence. For realizing a maximally compact spectral monitoring device, the multilayer filter stack was deposited directly onto the surface of an EUV photodiode. We find a good agreement between the theoretically predicted and experimentally measured transmission.

P 3

Numerical studies of colloid particle tracking in nano- capillary electrophoresis

P 4

Compact anomalous transmis-sion filters for EUV spectral monitoring

30 31

R. van der Beek, W. Vassen LaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam

We plan to measure the one-photon recoil velocity of a metastable helium-4 atom in a Ramsey-Bordé atom interferometer setup. High precision measurements of the one photon recoil velocity then allow an extremely accurate determination of the ratio h/M. Combined with well-known values for the Rydberg constant, the electron mass and the mass of the helium atom, this potentially provides an accurate determination of the fine structure constant α. Comparing this value of α with the value deduced from measurements of the electron g-factor provides a stringent test of quantum electrodynamics (QED) theory. For this project, a metastable helium BEC setup is currently being constructed. Here we report on first results of trapping atoms in a 1083-nm magneto-optical trap (MOT). In the near future we plan to transfer the atoms to a cloverleaf magnetic trap, where they will be cooled towards BEC and load-ed into a dipole trap at 1.5 mm.

G. Berden1, J. Martens1, L. Kluijtmans2, R. Wevers2, and J. Oomens1

1FELIX Laboratory, Institute for Molecules and Materials, Radboud University2 Radboud University Medical Center

The identification of molecular struc-tures by mass spectrometry (MS) drives advances in many areas of the bioanalyt-ical and clinical sciences. However, mass spectrometry alone provides only the mass/charge of an ion (m/z) and its fragmenta-tion behaviour under tandem MS (MS/MS) conditions, but does not directly access chemical structures. As a result, the iden-tification of ions with unknown molecular structures and the distinction of structural isomers having the same m/z and often exhibiting similar fragmentation chemistry are significant challenges in MS. Here, we use the combination of infrared spectros-copy and mass spectrometry (infrared ion spectroscopy, IR-IS) for the characteriza-tion of the structures of small molecules in mass spectrometry.

P 5

Towards measuring the fine structure constant in an ultracold metastable helium interferometer

P 6

Perpetual narrow-linewidth magneto-optical trap

C. C. Chen, S. Bennetts, B. B. Pasquiou, and F. SchreckVan der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam

We demonstrate a perpetual magneto-op-tical trap (MOT) of strontium atoms using the narrow 7.4-kHz linewidth transition of that atom. Efficient cooling of atomic vapor starting from room temperature requires a broad (MHz) linewidth tran-sition. Previous narrow-linewidth MOTs have relied on a two-stage process starting with atomic samples captured using a broad-linewidth MOT before switching to a narrow-linewidth transition. By contrast we execute both stages at the same time, sequentially in space, allowing continuous operation. We demonstrate a narrow-line-width MOT of >109 88Sr atoms at a temperature of ~20 µK with a continuous loading rate >108 atoms/s. This is an ideal atomic source to create a perpetual BEC, from which a perpetual atom laser can be outcoupled.

N. Cisternas, J.J.M. de Hond, G. Lochead, R.J.C. Spreeuw, H.B. van Linden van den Heuvell, and N.J. van DrutenIoP/WZI, Universiteit van Amsterdam

Atom chips offer unique opportunities to study quantum-degenerate gases. One of the challenges is to create tunable inter-actions. An appealing approach is to use Rydberg-mediated interactions to create strong, long-range, tunable, and switchable interactions.

We are exploring Rydberg excitation on the Celsius atom chip setup at UvA. The Rydberg character can be added either via direct excitation or by dressing. Advantag-es of dressing are that the decay is slower and that it provides a tuning knob for the interaction strength. Due to the large polarizability of Rydberg atoms and their proximity to the surface of the chip, the coherence of the excitation is currently limited by stray electric fields. In order to characterize these fields we measure Stark maps of both S- and D-states. The configuration of our system only allows us to compensate for undesired electric fields in one direction. We are investigating how fields in other directions can be character-ized by Stark shifts of D-states.

P 7

Perpetual narrow-linewidth magneto-optical trap

P 8

Rydberg excitation on an atom chip

32 33

T. Cremers, S. Chefdeville, N. Janssen, E. Sweers, S. Koot, P. Claus and S.Y.T. van de Meerakker. Molecular and Laserphysics, Institute for Molecules and Materials, Radboud University

Our understanding of physics on a molec-ular scale is enhanced by looking at inter-actions between molecules in a controlled environment. With the Stark decelerator, we produce bunches of molecules with a computer-controlled velocity and narrow velocity distribution. These tamed mo-lecular beams are ideally suited for novel molecular scattering experiments. With our recently built Zeeman decelerator we aim to replicate the effectiveness of the Stark decelerator for particles with a Zeeman shift. With supersonic beams of metastable helium atoms we characterize the capabili-ties of our new decelerator. We have explored the extent to which we can manipulate the velocity of these beams. We present the results, and discuss the prospects for future scattering experiments.

David Davtyan*, J.B. Naber, S. Machluf, C. Sanna, A.L. La Rooij, M.L. Soudijn, N.J. van Druten, H.B. van Linden van den Heuvell and R.J.C. Spreeuw *d.davtyan@uva.nlInstitute of Physics, University of Amsterdam

We present our recent results of research of atomic ensembles in two dimensional array of Ioffe-Pritchard type magnetic micro-traps on an atom chip. Due to adsorbate Rb atoms on the chip Rydberg excitations experience stray electric fields. We use Rydberg spectroscopy to measure electric fields and gradients, and their dependence on the distance to the surface [1].We also investigate several methods to modify the coverage of the surface by adsorbates which help to study temporal dynamics of the surface adsorbates through the stray electric fields. [1] J. Naber et al., ‘’ Adsorbate dynamics on a

silica-coated gold surface measured by Rydberg Stark

spectroscopy’’, J Phys B, Vol.49 N. 9 (2016)

P 9

Manipulating the velocity of metastable helium using the Nijmegen Zeeman decelerator.

P 10

Adsorbate dynamics on a sili-ca-coated gold surface measured by Rydberg spectroscopy

L. De Angelis1 F. Alpeggiani1, A. Di Falco2, L. Kuipers1 1AMOLF, Amsterdam, The Netherlands2University of St Andrews, St Andrews, UK

Phase singularities are locations in which the phase of a complex field is undeter-mined. In planar monochromatic random waves these are stationary points. Howev-er, as we vary the frequency of the waves which constitutes the random pattern, singularities move with Brownian statistics [1]. Singularities eventually annihilate after their persistence in the field, always in pairs. New pairs may also appear. With near-field experiments we determine the trajectories of phase singularities in optical random fields at varying frequency in the telecom region, hence being able to investigate the theoretically complicated problem of the lifelong fidelity [2], e.g. the correspondence between singularities creation and annihilation partners.

[1] X. Cheng, et al., Opt. Lett. (2014).

[2] M.V. Berry, Contemp. Phys. (2014).

E.A. Dijck, A. Mohanty, N. Valappol, K. Jungmann, and L. Willmann Van Swinderen Institute, University of Groningen

The lifetimes of the long lived D-levels in Ba+ ions provide access to the transition matrix elements of interest for atomic pari-ty violation experiments. We analyze quan-tum jumps of one or a few laser cooled 138Ba+ ions stored in a hyperbolic Paul trap. In this technique (electron shelving) the presence or absence of fluorescence from the laser cooling cycle is used to determine the quantum state of the ions as function of time. The long (half a minute) lifetime of the 5d 2D5/2 level makes the measurements highly sensitive to perturbing effects, such as interactions with background gas, and necessitates good control of experimental parameters over long timescales. We find no evidence for a dependence of the life-time on the number of stored ions.

P 11 P 12

Lifelong fidelity of phase singularities in optical random fields

Electron shelving in single and multiple Ba+ ions

34 35

L.S. Dreissen, R.K. Altmann, S. Galtier, K.S.E. EikemaLaserLaB, Vrije Universiteit Amsterdam

Quantum-Electrodynamics (QED) theory has been tested with extreme accuracy, e.g. based on laser spectroscopy of the 1S-2S transition in atomic hydrogen. However, Lamb shift measurements in muonic-hy-drogen have shown a sizeable discrepancy with QED theory (Science 339, 417-420(2013)). In order to investigate this problem we aim to perform spectroscopy on the 1S-2S transition in singly-ionized helium at ~30 nm. We developed a new method of Ramsey-comb spectrosco-py, which employs amplified frequency comb pulses for up-conversion to the XUV spectral range using high-harmonic generation (HHG). A single He+ ion will be sympathetically cooled by a single Be+ ion and confined in a planar-segmented rf-trap for long interaction times. We report on the progress towards realizing this experiment.

Patrick DupréLaboratoire de Physico-Chimie de l’Atmosphère, ULCO, Dunkerque

The molecular lineshape under linear ab-sorption regime is the object of numerous studies. Typically, the role of the collisions is of crucial importance and it requires an accurate modelling involving the molecule speed dependence. Under strong electro-magnetic field (EMF) conditions, which can be easily obtained inside high-finesse cavities, the usual lineshapes are strong-ly altered. For example, Lamb dips and crossover resonances can be observed1. The weak spectral extension of these resonances can give rise to a Doppler-free spectroscopy, and ultimately to metrology experiments.Under low pressure condi-tions, the residual sub-Doppler broadening is not any more monitored by the colli-sional processes, but by the interaction time (assuming very low radiative rates) between the molecules and the EMF. The full modelling of the lineshape remains to be elaborated, typically when different collisional regimes can be probed.We will try to present a formalism (under progress) appropriate to the molec-ular lineshapes under moderate saturated absorption, and non-monochromatic EMF. [1] P. Dupré, J. Opt. Soc. Am. B, vol. 32, p. 838 (2015).

P 13

Towards spectroscopy of the 1S-2S transition in singly ionized helium

P 14

Lineshape modelling in saturation regime

Dmitrii Egorov, Ronnie Hoekstra, and Thomas Schlathölter Zernike Institute for Advanced MaterialsUniversity of Groningen

Gas phase multiply protonated proteins can respond to near edge X-ray absorp-tion along two different channels: i) Non dissociative ionization and ionization accompanied by loss of small neutrals dominates for proteins with masses in the 10 kDa range. ii) Photofragmentation leading to formation of small sidechain related fragments such as immonium ions dominates for peptides in the 1 kDa range. Backbone scissions that deliver protein sequence information are generally weaker in both ranges. In a C 1s photoexcitation and photoionization study for a series of peptides and proteins with masses ranging from 0.5 kDa to more than 10 kDa, we investigated the transition between both re-gimes. The gas phase protonated molecules were trapped in a radiofrequency ion trap, exposed to synchrotron radiation from the U49/2-PGM1 beamline at Helmholtz-Zen-trum Berlin and investigated by time of flight mass spectrometry. The molecular fragmentation patterns upon photoioniza-tion can partly be related to the effective temperatures of the different proteins.

N. Ewald1, T. Secker1, J. Joger1, H. Fürst1, A. Glaetzle2, A. Negretti3, and R. Gerritsma1

1Institute of Physics, University of Amsterdam2Institute for Theoretical Physics, University of Innsbruck 3Zentrum für Optische Quantentechnologien, University of Hamburg

We report on an experiment that we are currently building up where we will study trapped ions interacting with atoms that are coupled to Rydberg states. Since the polarizability of the Rydberg atoms can be very large, the interactions between the ions and atoms will increase dramatical-ly as compared to the ground state case. We calculate that such interactions may be mediated over micrometers and could be used to entangle atoms and ions, to mediate spin-spin interactions or to study spin-phonon couplings [1]. We discuss our experimental approach as well as a detailed theoretical analysis of a Rydberg atom-ion interface unit-cell.

[1] T. Secker et al., arXiv:1602.04606 (2016).

P 1 5 P 16

Near edge X-ray absorption mass spectrometry of gas phase pro-teins: the influence of protein size

Trapped ions in strongly polarizable media

36 37

Youwen Fan,1 Rob Lammerink,1 Ruud M. Oldenbeuving,2 Peter J. M. van der Slot,1

and Klaus-J. Boller1

1Laser Physics and Nonlinear Optics group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, the Netherlands2SATRAX B.V., Enschede, the Netherlands

Reducing the spectral linewidth of diode lasers can be achieved via frequency selec-tive feedback from a long external cavity. However, extending the cavity length also decreases the longitudinal modes spacing, which renders single-mode oscillation challenging. Here we propose a novel semiconductor-glass hybrid laser where frequency selection is based on a high index-contrast Si3N4-SiO2 glass waveguide circuit that incorporates three microring resonators (MRRs) and a long cavity length on a chip. Two of the resonators are used for coarse frequency selection while a third MRR with a high quality factor (Q > 100,000) serves for selection of a single longitudinal mode. Modeling such hybrid lasers with cavity lengths beyond 10 cm confirms the potential for sin-gle-mode oscillation with a spectral band-width at the one-kHz-level.

Adonis Flores, Wim Vassen, Steven Knoop LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam

Ultracold collisions between alkali-metal and metastable triplet helium atoms provide a unique interplay between inter-species Penning ionization and Feshbach resonances, strongly dependent on the spin (hyperfine and Zeeman) states of the atoms. Recently we have realized the first optically trapped mixture of alkali-met-al and He* atoms, using our previously developed cooling scheme [1,2]. This allows us to measure the trapping lifetime for different spin mixtures and obtain the spin-dependent Penning ionization loss rates. We compare our results with multichannel quantum-defect theory [3,4] to determine whether loss is universal or not in this collision system.

[1] H. P. Mishra, A. S. Flores, W. Vassen, S. Knoop,

Eur. Phys. J. D 69, 52 (2015)

[2] A. S. Flores, H. P. Mishra, W. Vassen, S. Knoop,

Appl. Phys. B 121, 391 (2015)

[3] Z. Idziaszek, P. S. Julienne, Phys. Rev. Lett. 104,

113202 (2010)

[4] K. Jachymski et al, Phys. Rev. Lett. 110, 213202 (2013).

P 17

Towards sub-kHz semiconductor-glass waveguide hybrid lasers

P 18

Spin-dependent Penning Ioniza-tion loss in ultracold, optically trapped mixtures of alkali-metal and metastable helium atoms

Nolan Foley1, Leon Boschman1,2, Ronnie Hoekstra1, Stephanie Cazaux2, and Thomas Schlathölter1

1Zernike Institute for Advanced Materials, University of Groningen2Kapteyn Institute, University of Groningen

Superhydrogenation of ionic /neutral polycyclic aromatic hydrocarbons (PAHs) is of great relevance, as it might influence PAH lifetimes in harsh astrophysical envi-ronments and contributes to the formation of H2, the most abundant molecule in the universe. We have studied superhydrogena-tion of trapped gas-phase coronene cations exposed to a thermal atomic H beam. Variation of H exposure time allowed for addition of 1-23 H atoms and for the determination of the respective adsorption barriers. The observed magic numbers, i.e. hydrogenation states of particular stability, and the observed hydrogenation dynam-ics are in good agreement with preferred binding sites and chemisorption barriers as determined by means of density functional theory (DFT). Hydrogenation proceeds via a well-defined sequence of adsorption sites. Furthermore, comparison of H and D attachment reveals that hydrogen attach-ment is competing with hydrogen abstrac-tion, implying direct H2 production. The latter has profound consequences for the formation of cosmic H2.

J.G.H. Franssen1,2, E.J.D. vredenbregt1,2, O.J. Luiten1,2, Ronnie Hoekstra1, Stephanie Cazaux2, and Thomas Schlathölter1

Group Coherence & Quantum technology1

Institute for Complex Molecular Systems2

Eindhoven University of TechnologyP.O. Box 513, 5600 MB, The Netherlands

We are developing an ultra-fast and ultra-cold electron source based on a grating magneto optical trap, RF acceleration and RF (de-)compression techniques. The electrons will be created by near-threshold, femtosec-ond photoionization of a laser-cooled and trapped gas. The electron cloud is extracted from the plasma by a DC electric field and is further accelerated to energies of 100s keV by means of radio frequency accel-eration techniques. This is possible while maintaining the electron beam quality, electron source temperatures of 10 K[1].The setup can be used to create ultra-short electron bunches (i.e. 100 fs) by applying RF compression techniques. This makes the source ideal for time resolved pump-probe crystallography of macromolecules. Secondly, the energy chirp can be removed by RF decompression techniques, resulting in low energy spread electron pulses. This also makes the source a viable candidate for electron microscopy and coherent imaging.

[1] Engelen, Nature Commun., 4, 1693 (2013)

P 19

Hydrogen attachment versus hydrogen abstraction on gas-phase coronene cations

P 20

Radio frequency acceleration and manipulation of ultra-cold electron bunches

38 39

H. Fürst, J. Joger, N. Ewald, T. Secker and R. GerritsmaInstitute of Physics, University of Amsterdam

A setup for realising a hybrid system of ultra-cold atoms and ions is presented. Recent theoretical analysis has shown that the trapping field of the ions can limit attainable temperatures in hybrid atom-ion systems. We mitigate this problem by em-ploying the ion-atom combination with the highest conveniently accessible mass ratio: 174Yb+ and 6Li. Combining ion trapping technology with ultra-cold lithium poses particular challenges that we address on this poster. We present numerical simula-tions showing that the s-wave limit may be reached in our setup, opening up the possibility of studying atom-ion Feshbach resonances [2].

[1] M. Cetina et al., Phys. Rev. Lett. 109, 253201 (2012).

[2] M. Tomza, et al., Phys. Rev. A 91, 042706 (2015).

Figure: Ion trap with atom loading platform.

Ke Guo and Femius KoenderinkFOM Institute AMOLF

Depending on the strength of diffractive coupling, distributed feedback (DFB) lasers can support different lasing modes with distinctive spatial intensity distri-butions. Compared with conventional dielectric distributed feedback (DFB) lasers, a plasmonic DFB laser enjoys much stronger scattering from the plasmonic lattice with the cost of metallic losses. The coupling strength of the plasmonic lattice determines the mode purity and efficiency of a plasmonic DFB laser. We measure spatial intensity of the plasmonic DFB lasers based on square arrays of Ag nanoantennas, aiming to assess how small the smallest plasmonic array DFB laser can be, and what spatial coherence properties are. Array size and plasmonic scattering strength offer easy approaches to the opti-mization of the plasmonic DFB lasers.

P 21

A hybrid atom-ion trap for ultra-cold Li and Yb+

P 22

Spatial intensity in plasmonic distributed feedback laser

Y. Hao, A. BorschevskyUniversity of Groningen

Theories unifying gravity with the other in-teractions suggest the possibility of spatial and temporal variation of dimensionless fundamental physical constants, such as the fine structure constant, α=e2/ћc, and the proton to electron mass ratio, μ=mp/me.

Diatomic molecules are very promising probes for variation of fundamental con-stants (VFC), as their spectra can be very sensitive to both α and μ, making it possi-ble to look for change in both constants in a single experiment.

Nearly degenerate levels with different sensitivity to VFC may provide huge en-hancements of the relative variation, since δω/ω tends to infinity when the distance between the levels ω is close to zero. However, locating such fortuitous level combinations is not a trivial task.The poster will present some schemes for identifying rovibrational transitions with optimal sensitivity to VFC in diatom-ic molecules and cations. Examples of promising molecules, which benefit from very low energy rovibrational transitions between either the nearly degenerate sub-levels of their X 2Π ground states (As2

+, Sb2+),

or between different electronic levels (I2, Cl2

+) will be discussed.

Javier Hernandez-Rueda1,2, Jasper Clarijs1, Dries van Oosten1, Denise M. Krol2 1 Debye Institute for Nanomaterials Science, Utrecht University2 University of California Davis

We have investigated the effect of the wavelength on the fabrication of optical waveguides via laser direct writing inside glass. The size of the laser-inscribed waveguides, the material modification thresholds and the writing energy range have shown a strong dependence for writ-ing wavelengths ranging from ultraviolet (400 nm) to near infra-red (1300 nm). Numerical simulations that consider the laser-excited electron plasma dynamics (fig. a) along with Gaussian beam propa-gation theory have been used to calculate the laser-affected volume size that has been further compared with the experimental results (fig. b). This study yields insight on how to predict and design optical wave-guide’s features (fig. c) and also aids to understand the underlying physical mecha-nisms linked to laser-glass interaction.

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Diatomic molecules as probes for variation of fundamentalconstants

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The influence of femtosecond laser wavelength on waveguide writing features inside transparent ma-terials

40 41

Anne de Beurs, Sylvianne Roscam Abbing, Javier Hernandez-Rueda, Dries van OostenDebye Institute for Nanomaterials Science, Utrecht University

We have experimentally and theoretical-ly investigated the scattering properties of gold nanoparticles by combining a quadrupole ion trap, a laser-based imaging system and Mie formalism. The intensity of the scattered light (Is) by the suspended particles was imaged by a CCD camera at an angle of 90º with respect to the beam propagation axis. Then, the scattered inten-sity dependence with the polarization state (φ) and the wavelength (λ) of the incident beam was studied. In order to characterize the particle diameter, a direct comparison of the calculations based on Mie theory with the Stokes’ parameters retrieved from the experimental Is(φ) curves was done. This ion trap will offer the ideal platform to investigate femtosecond laser ablation of trapped gold nanoparticles in vacuum.

J.J.M. de Hond, N. Cisternas, G. Lochead, R.J.C. Spreeuw, H.B. van Linden van den Heuvell, and N.J. van DrutenIoP/WZI, Universiteit van Amsterdam

Rydberg states are characterized by long-range and tunable interactions, which makes them interesting for applications in quantum information. Their lifetimes, however, are of the order of µs, which is detrimental in most cases. By mixing only a small amount of Rydberg character into the ground state, dressing provides a way out.

Presently, dressing has been observed in a few-atom system and on an optical lattice. In Bose-Einstein condensates, however, its observation has proven elusive. It is particularly hard to measure in 3D due to collective effects caused by Rydberg block-ade. We have been undertaking simulations of dressing in 1D, which relates to our 1D BEC experiment. Due to the difference in geometry, dressing is more promising in 1D than it is in 3D [1]. Additionally, we have explored finite-temperature systems using the modified Yang-Yang model and the stochastic Gross-Pitaevskii equation. Different approaches to the role of collec-tive effects have also been explored.

[1] Plodzien et al., arXiv:1605.04440, 2016

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Scattering properties of gold nanoparticles inside a quadrupole ion trap

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Simulations of Rydberg dressing at finite temperatures

Tarun Johri, Yuri van der Werf, Bart Hoekstra, Servaas Kokkelmans, Edgar Vredenbregt A. BorschevskyCoherence and Quantum Technology group, Eindhoven University of Technology

Creating ultracold Rydberg atoms in lattic-es imprinted with a spatial light modulator offers the possibility to simulate quantum processes. Strong dipole forces between Rydberg atoms provide the required cor-relations between lattice sites. With a high ground-state atomic density per lattice site, blockade phenomenon may induce single Rydberg atom occupancy per lattice site. Readout of resulting patterns requires sin-gle-atom detection with spatial resolution. The grand challenge is to create systems of interacting Rydberg atoms with scalability.

So far, we have achieved spatial imaging of Rydberg atoms using ion optics and incor-porated in-vacuo aberration correction for imprinted light patterns. Presently, we are studying the effect of dipole blockade on Rydberg excitation statistics. For this we have set up a tuneable Rydberg excitation laser system using an ultra stable reference. Measurements of spatial correlation func-tions show that achieving a blockade radius of 10 µm is possible. Combined with a dark-spot MOT, this is sufficient to achieve precisely one Rydberg atom per lattice site.

Lutz Langguth, Romain Fleury, Andrea Alù, and A. Femius KoenderinkCenter for Nanophotonics, FOM Institute AMOLF, Science Park 102, 1098XG Amsterdam

Drexhage’s seminal observation that spon-taneous emission rates of fluorophores vary with distance from a mirror uncovered the fundamental notion that a source’s environ-ment determines radiative linewidths and shifts. Further, this observation established a powerful tool to determine fluorescence quantum yields. We present the direct analogue for sound. We demonstrate that a Chinese gong (for sample see figure) at a concrete wall experiences radiative corrections to linewidth and line shift, a classroom demonstration analogue of the radiative level shifts and linewidth changes that atoms experience at mirrors. For each gong mode we can extract the intrinsic radiation efficiency, despite the fact that we performed an experiment in which no absolute energy balance needs to be meas-ured, instead relying on impulse excitation by a wooden marble, and pickup by a mi-crophone speaker coil. Beyond acoustics, our experiment opens new ideas to extend the Drexhage experiment to metamaterials, nanoantennas, and multipolar transitions.

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Optically imprinted rydberg lattice

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Drexhage’s experiment for sound

42 43

I.M.Palstra, N.D.Kosters, F.Alpeggiani, L.KuipersFOM Institute AMOLF, Science Park 104, Amsterdam, kosters@amolf.nl

Conventional circular dichroism measure-ments rely on the excitation asymmetry in chiral molecules for circularly polar-ized light (CPL) of opposite handedness. Recently, chiral plasmonic nanostructures were demonstrated to have electromagnetic near fields of which the optical chirality (C) exceeds that of CPL (CCPL=1). These ‘superchiral’ fields induce enhanced excita-tion asymmetry in chiral molecules1. With simulations we show that the near field of conventional silicon photonic crystal waveguides (PhCWs) can contain values of local C up to ten times larger than CPL (Figure 1a). However, sensing of molecules is impossible with these wave-guides as the total C is zero. A nonzero total C, including local C>60, was realized by breaking all mirror symmetries through a shifting of air holes (Figure 1b).[1] Tang, Y. & Cohen, A. E. Science 332 (2011)

Nishant Kumar1, 2 and Paul C. M. Planken1, 2 1EUV Targets Group, ARCNL2Institute of Physics, University of Amsterdam

Abstract: An experimental setup for broad-band time resolved infrared spectroscopy has been built. Using this setup, strong ul-tra-wide (~20 THz) coherent infrared puls-es are made using air plasma generation with two colour laser pulses. These pulses are detected using air biased coherent detection. In the detection process, the time dependent electric field is measured as a function of time (shown in figure 1), rather than intensity. The motivation behind this work is to measure mid/far infrared dielec-tric properties of metals and metal plasmas (specially tin and tin plasma), as a function of time during and after the excitation of metals with a high power laser pulse.

Figure 1: Ultrafast terahertz electric field as a function

of time, measured using air biased coherent detection.

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Superchiral near fields in photonic crystal waveguides

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Towards ultra-wideband infrared time-resolved spectro-scopy of tin and tin plasma

Giada La Gala, Rick Leijssen, Lars Freisem, Juha Muhonen, and Ewold VerhagenFOM Institute AMOLF, Amsterdam

In a cavity-optomechanical system, the influence of a mechanical resonator’s dis-placement on the optical frequency of the cavity allows to measure its motion with ultrahigh sensitivity. We investigate sliced photonic crystal nanobeams, in which the optomechanical interaction is extraordinary large due to subwavelength confinement of the light in the nanoscale gap separating the beams. Combined with high optical quality factors, these systems operate in a regime where Brownian motion induces optical frequency modulation larger than the cavity linewidth, meaning optome-chanical measurement becomes highly nonlinear. We show how the nonlinear stochastic behavior of such systems can be described. Because of the direct analogy to the promising regime of single-pho-ton strong optomechanical coupling, our results provide insight in the phenomena that can be expected when this nonlinearity is present even down to the amplitude of mechanical zero-point motion.

A. J. van Lange, K. Voutyras and D. van Oosten Debye Institute for NanoMaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University

In our setup, we transport ultracold atoms to nanophotonic structures using a series of (magneto-) optical traps. In the final stage, atoms can be slowly transported above dif-ferent transparent samples using a standing wave trap (optical conveyor). The optical conveyor can move by introducing a fre-quency difference in the counterpropagating beams. The coupling of ultracold-trapped at-oms and the field of nano-optics is realized with a free standing SiN waveguide bridge of 200 x 200 nm cross section. Resonant light to Rubidium transitions is coupled in and out using free standing surface grating couplers at both sides of the bridge. The change in the transmission indicates light-matter interaction in the nano-scale. To detect this signal properly, we use RF-heterodyne detection.

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Nonlinear transduction of Brownian motion in a nano- optomechanical system.

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Ultracold atoms close to nanoscale waveguides

44 45

T. B. M. van Leent, S. Bennetts, C. C. Chen, B. B. Pasquiou, and F. SchreckVan der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam

We are developing tunable, narrow-linew-idth, external cavity diode lasers (ECDLs) for applications in atomic physics [1]. These applications include spectroscopy, laser cooling and trapping, as well as the creation of atom-optics elements. Our goal is to demonstrate a laser that can be locked to narrow transitions with improved long term stability compared to commercial systems. Our approach is to isolate the ECDL from external disturbances, such as temperature changes, sound, or vibrations. We use a massive laser housing with high heat capacity, which we decouple from the environment thermally and acoustically. The performance of our lasers is compared with commercial systems.

[1] C. E. Wieman and L. Hollberg, Using diode lasers

for atomic physics, Rev. Sci. Instrum. 62, 1 (1991).

J. Mak, H. Yuan, N. Banerjee, H.M.J. Bastiaens, A.J.H.M. Rijnders, K.-J. BollerMESA+ Institute for Nanotechnology, University of Twente

On-chip modulation, optical switching and isolation would be greatly facilitated if one had access to the strongest type of non-linear optical effects: the ones of second order. However, in glass platforms that are preferred when ultra-low propagation loss is required, such as silicon nitride, the bulk X(2)-coefficient is zero due to the amorphous structure of the glass. We aim to equip silicon nitride waveguides with a second-order nonlinearity by covering them with a X(2-nonlinear thin-film. The issue to be solved is that a crystalline film needs to be grown on an amorphous substrate. We address this issue by first depositing as a buffer layer crystalline nanosheets on a glass test-plate [1], before depositing a 200 nm thick lithium niobate layer. The crystallinity and the degree of X(2 nonlinearity are under investigation, for instance via second harmonic generation.

[1] M. Bayraktar et al., Nanosheet controlled epitaxial

growth of PbZr0.52Ti0.48O3 thin films on glass substrates.

Appl. Phys. Lett. 105 (13), 132904 (2014).

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Tunable narrow-linewidth external cavity diode lasers

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Second-order nonlinear effects in silicon nitride waveguides covered by a nonlinear thin-film

J. Mandon, S.M. Cristescu, F.J.M. Harren Life Science Trace Gas Facility, Radboud University, Nijmegen, NL

Well-established frequency comb sources offer great opportunities for broadband precise measurements in gas sensing applications. The recent development of mid-infrared frequency comb sources is of great interest in this field, as most of the molecules exhibit their strongest rotation-al-vibrational transitions in the mid-infrared region. Dual-comb spectroscopy is evolved from traditional Fourier transform spec-troscopy (FTS), taking advantages of high brightness of light source, high resolution and fast acquisition time.We report on an optical parametric oscillator (OPO) based on two periodically poled lithium niobate crystals generating light in the 3-5 µm wavelength region. The unique two-crystal ring cavity design offers inter-esting stability of the frequency combs. The P, Q and R branches of the υ3 vibrational transitions of methane are simultaneously measured between 2850 cm−1 and 3200 cm−1 within 0.1 s, giving a bandwidth of more than 350 cm−1 and a spectral resolution of 0.2 cm−1. At the same time, the dispersion information is retrieved with the benefit to be immune to the intensity fluctuations of the laser power.

Evangelos Marakis, Wouter van Harten, Ravitej Uppu, and Pepijn W.H. Pinkse Complex Photonic Systems (COPS), MESA+ Institute for Nanotechnology, University of Twente

State of the art authentication systems depend on physical unclonable functions (PUF), physical keys that are assumed unclonable due to technological constraints. Multiple scattering media are considered as ideal optical PUFs, because when illumi-nated by coherent light, a unique random interference pattern is generated. This response is a speckle pattern and de-pends on the illumination pattern conditions and the details of the scattering medium itself. The assumption of unclonability relies on the notion that a speckle pattern is extremely sensitive to the exact location and shape of the scatterers. We attempt to falsify this assumption by investigating the possibility to create copies of a multiple scattering medium using direct laser writing.

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Mid-Infrared Dual-comb in gas sensing applications

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Reproducibility of artificial multiple scattering media

46 47

E. Mjekiqi, E. Castellano-Altable, D. Egorov, R. Hoekstra and T. SchlathölterZernike Institute for Advanced Materials, University of Groningen

DNA stability with respect to oxidative stress and ionizing radiation plays a key role in aging and in cancer development. It is well known that in DNA an initial excitation, i.e. an electron-hole pair, can migrate long distances before it reaches a site where it manifests as damage. Recent theoretical studies support the concept, that DNA contains sacrificial guanine-rich sites able to trap excitations and protect sensi-tive DNA regions from damage, with the human telomere sequence TTAGGG being a particularly efficient trap [1].

We have studied soft X-ray photoioniza-tion and photofragmentation of gas-phase deprotonated oligonucleotides TTAG-GG-CCGCCG close to the C, N and O K-edges. Besides non-dissociative electron detachment, the formation of negatively charged fragments is observed, most of which originate from scissions in the tel-omere GGG region. Furthermore we find, that DNA damage is generally suppressed for photoabsorption in the nucleobases.

[1] E. Cauët, J. Biom. Struct. Dyn. 29 (2011) 557

Faisal Nadeem1, Berber Postma2, Simona Cristescu1, Geert Postma2, Julien Mandon1, Frans.J.M. Harren1

1 Molecular and Laser Physics2 Analytical Chemistry Radboud University Nijmegen, NL

The sensitivity of absorption measure-ments of a molecular concentration in the gas phase can be strongly improved using Off-Axis Integrated Cavity Output Spectroscopy (IA-ICOS). However, the sensitivity of the system is limited by the low power relative the detector noise due to the highly reflective mirrors [1,2]. To improve the power throughput, a third mirror is place before the cavity to re-inject the reflected light from the cavity into the cavity. Position, radius of curvature, entrance hole, cavity dimensions need to be optimized for optimal power enhance-ment and long interaction path length. We used a Genetic Algorithm in combination with point vector ray tracing vector method to model the interaction inside the optical resonator and enhance the sensitivity of OA-ICOS. We were able to re-inject 864 re-injected spots to the absorption cavity yielding enhancement factor of 864.References

[1] R. Centeno et al. Sensors and Actuators B 203,

311-319 (2014)

[2] Centeno, R., et al., Optics Express, 22, 23, 27985-

27991 (2014)

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Do telomere sequences protect DNA against photofragmentation?

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Optical resonators inspired by Genetic algorithm

Figure 1:

Spot pattern

on re-injection

and end

mirrors.

Oleksiy Onishchenko, Sergey Pyatchenkov, Georgios A. Siviloglou, and Florian Schreck Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam

We have designed and assembled a new multi-chamber quantum gas apparatus with the goal of exploring topological band struc-tures [1] and engineering many-body Ham-iltonians [2]. Ultimately we plan to probe and manipulate quantum gases in a lattice at the single-atom level using quantum gas microscopy [3]. To reach our goals, we have chosen fermionic strontium because of its particularly suitable properties, such as the existence of narrow intercombination lines, metastable excited electronic states, and a large number of collisionally-stable SU(N=10)-symmetric nuclear spin states [4].

[1] N. Goldman et al., Rep. Prog. Phys. 77, 126401 (2014).

[2] I. Bloch, J. Dalibard, and W. Zwerger, Rev. Mod. Phys.

80, 885 (2008).

[3] S. Kuhr, Natl. Sci. Rev. 3, 170 (2013).

[4] S. Stellmer, R. Grimm, and F. Schreck, Phys. Rev. A 87,

013611 (2013).

L.J.M. Kempkes, J. Martens, J. Grzetic, G. Berden, J. Oomens FELIX Laboratory, Radboud University

In most applications, MS/MS methods are used merely in an empirical fashion. Nonetheless, obtaining a fundamental understanding of the fragmentation reac-tions to the level of the underlying potential energy surface has also received ample attention. Here, it is often encountered that even for seemingly simple systems, a plethora of rearrangements accompanying the dissociation reaction are conceivable. Infrared ion spectroscopy has emerged as a powerful structural tool in mass spectrom-etry. In combination with a modified ion trap mass spectrometer, we show that it is possible to identify structures after multiple stages of MSn. We use this instrument to build a structural map of gaseous deamida-tion (elimination of NH3) reaction products of four protonated dipeptides containing either an asparagine or a glutamine residue.

P 39

Building a versatile quantum gas experiment for fermionic strontium

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Deep molecular structure probing in mass spectrometry by IR ion spectroscopy: deamidation reacti-on networks

48 49

Pritam Pai1, Jeroen Bosch1, Allard Mosk1

1 Utrecht University, Utrecht, The Netherlands

In optics, the transmission matrix of a sample, which is part of the larger scatter-ing matrix, is an important property since it relates the incident light field to the transmitted one [1]. Using monochromatic light, the transmission matrix can be meas-ured in a spatial basis set by scanning the incident beam with a known beam profile across the scattering material and recording the corresponding transmitted fields [2]. Eigenwaves of this matrix are waves which might lose their initial intensity but emerge with exactly the same beam profile.Once the transmission matrix of such a sample is determined, its eigenvalues and corresponding eigenvectors can be numeri-cally calculated. In this poster presentation, we will explore the mathematical and physical properties of these transmission eigenwaves and propose experiments to expose them. We also investigate the possibility of transmitting an arbitrary image through a scattering sample without introducing significant spatial distortions.

[1] C.W.J. Beenakker, Rev. Mod. Phys., 69, 731 (1997)

[2] S.M. Popoff, Phys. Rev. Lett, 104, 50 (2010)

Nikhil Parappurath, Filippo Alpeggiani, Kobus Kuipers and Ewold VerhagenFOM Institute AMOLF, Amsterdam, The Netherlands.

We investigate the origin of asymmetric transmission (AT) in chiral dielectric photonic crystals. AT originates from the tailorable polarization properties of the eigenmodes of the structure. We develop a theory that can fully predict the scattering matrix from the eigenmode properties for any structure with an arbitrary number of modes, and use it to derive AT. The theory shows that AT for a single mode is funda-mentally limited by reciprocity. By exploit-ing the obtained theoretical understanding, we show that it is possible to achieve near-unity AT with suitable designs.

P 41

Properties of transmission eigenvectors in strongly scattering media

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The origin and limit of asymmetric transmission in chiral photonic crystals

Figure: a) Calculated transmission spectrum for the proposed structure (unit cell is shown inset). b) Scatterplot of AT for isolated modes as a function of non-resonant reflection coefficient r, calculated for randomly chosen eigenmode polarizations.

A. Ciamei, V. Barbé, A. Bayerle, B. Pasquiou and F. Schreck Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam

We are pursuing the creation of ultracold RbSr ground state molecules, by binding the two atomic species while keeping full control over external and internal quantum states. These dimers can exhibit a strong, tunable electric dipole moment (up to 1.5 Debye), and possess one unpaired electron. These properties would allow for example to simulate exotic spin models in optical lattices, and to form dipolar crystals. Such molecules also open doors to studies of chemical reactions at the quantum level.

We have created a 84Sr-87Rb Mott insu-lator and investigated STIRAP molecule association on the forbidden 1S0-

3P1 intercombination line. We found only very weak transitions between free atoms and optically excited molecules, hindering us from coherently creating molecules. Using mass-scaling, our spectroscopy data point to a much more promising STIRAP path in 87Sr-87Rb mixtures, which we are currently exploring. Furthermore, we have developed a STIRAP light-shift compensation method, benchmarked by creating Sr2 molecules with more than 80% efficiency.

Sayan Patra1, T.J. Pinkert1, K.S.E. Eikema1, W.M.G. Ubachs1, J.C.J. Koelemeij1

1Department of Physics and Astronomy and LaserLaB, Vu University Amsterdam

High-resolution laser spectroscopy on (ν,L):(0,2)-->(8,3) ro-vibrational overtone of trapped, sympathetically cooled HD+

ions has been demonstrated with relative frequency uncertainty of 1.1 parts-per-billion, the resolution almost exclusively limited by first-order Doppler broadening. To improve on this, Doppler-free, quasi-de-generate two-photon spectroscopy on the (ν,L):(0,3)-->(4,2)-->(9,3) overtones at 1.44 µm is underway in our setup in Amsterdam. Realistic simulation with parameters from our experimental setup affirms the feasibili-ty of spectroscopy at the level of 1×10-13 or below. This would allow a test of molecular theory including relativistic and quantum electrodynamic corrections at the level of 4×10-11. Agreement between theory and experiment would enable an improved determination of proton to electron mass ratio µ over the current most precise deter-mination. Also, a better constraint can be imposed on the hypothetical “fifth forces” and rolled-up higher dimensions.

P 43

About weakly bound dimers of rubidium and strontium

P 44

Doppler-free two-photon spectroscopy of trapped, laser-cooled HD+ ions

50 51

A.P.P. van der Poel1, P.C. Zieger1,2, S.Y.T. van de Meerakker3, and H.L. Bethlem1

1 LaserLaB, Department of Physics and Astronomy, VU University Amsterdam2Fritz-Haber-Institut der Max-Planck- Gesellschaft, Berlin3Radboud University Nijmegen, Institute for Molecules and Materials

We study the structure in collision cross-sec-tions of ND3+H2 and ND3+Ar collisions [1] using a synchrotron that stores packets of neutral ND3 molecules [2]. The advantages of using a synchrotron are: (i) The collision partners move in the same direction as the stored molecules, resulting in low collision energy (down to 10cm-1); (ii) by storing molecules many roundtrips, the sensitivity to collisions is greatly enhanced.We present the current status of the exper-iment: Characterization of collision signal in the synchrotron, and measurement of the ND3+Ar cross-sections for collision energies between 45 and 115cm-1.

[1] A. v/d Avoird, G.C. Groenenboom, priv. comm.

[2] Zieger et al., PRL 105, 173001 (2010)

1.Marco A. G. Porcel, 2.Florian Schepers, 3.Jörn P. Epping, 2.Tim Hellwig, 3.Marcel Hoekman, 3.Arne Leinse,3.René G. Heideman, 4.Albert van Rees, 1.Peter J. M. van der Slot, 5.Chris J. Lee, 6.Robert Schmidt, 6.Rudolf Bratschitsch, 1,2.Carsten Fallnich , and 1.Klaus-J. Boller 1.LPNO, UTwente, The Netherlands2.Institute of Applied Physics, Westfälische Wilhelms-Universität, Germany3.LioniX B.V.,The Netherlands4.XiO Photonics B.V., The Netherlands5.XUV Optics, MESA+ Institute for Nanotechnology, UTwente, The Netherlands6.Institute of Physics, Westfälische Wilhelms- Universität, Germany

We demonstrate on-chip generation of supercontinuum radiation using integrated silicon nitride optical waveguides, in which we achieve the largest-ever on-chip spectral bandwidth (468 THz) driven at telecommu-nication wavelengths. The double-octave spanning supercontinuum is generated using a mode-locked laser at a wavelength of 1.5 µm with a pulse duration of 120 fs. The waveguide cross section (1.0 x 0.9 µm) is designed for providing anomalous disper-sion across the entire telecommunication range. The supercontinuum spectra extend from the visible, at around 520 nm, up to the mid-infrared, to 2580 nm (instrumentation limited), spanning more than 2.3 octaves at -30 dB full width via a single pump source.

P 45

Studying cold collisions in a molecular synchrotron

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Two-octave spanning on-chip supercontinuum generation at telecom wavelengths using silicon nitride wavegu

J.J. Renema, W.R. Clements, J. Boutari, W.S. Kolthammer, I.A. Walmsley Oxford University Department Of Physics

Boson sampling is a form of non-universal quantum computation in which the challenge is to sample the outputs of a network of inter-ferometers fed by single photons. Sampling from the output statistics of the network is thought to be computationally hard [1]. Build-ing a boson sampler which is large enough that a classical computer cannot in any reasonable time reproduce its output is thought to be a promising route to quantum supremacy. How-ever, to date, boson sampling experiments are limited to a few (3-6) photons, due to the difficulty of generating single photons.

We theoretically explore alternate methods and platforms for boson sampling. We consider fiber-loop based architectures. We will demonstrate that a single fiber loop is insufficient to perform boson sampling, and we will discuss the requirements on a two-loop system.

Secondly, we will consider a related photon sampling problem using as initial states bright squeezed vacua. We will use a recently proposed classicality criterion [2] to evaluate the practical nonclassicality re-quirements on the interference of two-mode squeezed vacua.[1] S. Aaronson, A. Arkhipov, arXiv:1011.3245

[2] S. Rahimi-Keshari, T.C. Ralph, C.M. Caves arXiv:

1511.06526

R.J. Rengelink, R.P.M.J.W. Notermans and W. VassenLaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam

We are aiming for a new measurement of the 4He-3He isotope shift of the 23S-->21S transition at 1557 nm in order to extract the difference in nuclear charge radii. An ac-curacy comparable to current experiments on muonic helium is achievable if we can push the uncertainty of our previous determination from the level of a few kHz to a few hundreds of Hz. This measure-ment was done using helium atoms cooled to quantum degeneracy and trapped in an optical dipole trap. The biggest uncertainty was the extrapolation of the AC-Stark shift of the trapping laser. In order to solve this problem we have built a laser system at the 319.815 nm magic wavelength, producing over 2W of UV light, and used it to trap atoms. We will present our first results on trapping helium in a crossed-beam magic wavelength ODT and our progress in ex-actly pinpointing the magic wavelength.

P 47

Unconventional Boson samplings

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A magic wavelength trap for ultracold 4He and 3He: cancelling the Stark shift on the 23S -->21S transition

52 53

Jasper van Rens, Wouter Verhoeven, Erik Kieft, Peter Mutsaers, Jom LuitenGroup Coherence & Quantum TechnologyEindhoven University of TechnologyP.O. Box 513, 5600 MB, Netherlands

We are developing microwave cavities to chop a low-emittance electron beam into 100 fs bunches at a repetition rate of 3 GHz. Accurately synchronized to a mode-locked laser, these bunches can be used for ultrafast time-resolved TEM [1]. We show recently measured time-of-flight femtosecond electron energy loss spectra (ToF-FEELS) of graphite measured in a horizontal SEM-based setup using a second ‘streak’ cavity. With this cavity we have directly measured an electron pulse length of 2.7 ps and an EELS energy resolution of 12 eV. Currently we use this setup to study the ponderomotive scattering of electron bunches off a standing wave of high inten-sity laser light. At the moment of writing we have already achieved the spatial and temporal overlap of two 30-fs laser pulses. If successful, we plan to study diffraction of electrons on a standing wave of light, the so-called Kapitza-Dirac effect.

[1] Oral presentation #: W. Verhoeven, Ultrafast

Time-resolved Electron Microscopy

Oleg Selig, Roel Siffels and Yves L.A. RezusFOM institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands

Infrared nanoantennas are metallic nano-structures that have the ability to confine electromagnetic fields to volumes many times smaller than the diffraction limit. The strong field enhancement accompa-nying this process provides an avenue for amplifying the spectroscopic signal of molecules located in the nanoenvironment of the antennas. Here we have used this idea and developed a novel experimental technique for performing ultrasensitive ultrafast vibrational spectroscopy on ultrathin layers of material1,2. Using our nanoantenna-based technique we have observed transient absorption signals that are amplified by almost five orders of magnitude compared to standard vibration-al pump-probe spectroscopy. We discuss the nonlinear amplification mechanism in terms of a multiple-scattering formalism, and we show that it can be understood as form of electromagnetically-induced transparency.1O. Selig, R. Siffels & Y.L.A. Rezus, ‘Ultrasensitive ultra-

fast vibrational spectroscopy employing the near field of

gold nanoantennas‘ Phys. Rev. Lett. 114, 233004 (2015)2Y.LA. Rezus & O. Selig, ‘Impact of local-field effects on

the plasmonic enhancement of vibrational signals by in-

frared nanoantennas’, Optics Express 24, 12202 (2016)

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Ultrashort free electron pulses scattering on matter and light

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Ultrasensitive ultrafast vibra-tional spectroscopy employing the near field of gold nanoan-tennas

Matthijs Jansen, Denis Rudolf, Lars Freisem, Kjeld Eikema and Stefan WitteVrije Universiteit Amsterdam and Advanced Research Center for Nanolithography (ARCNL)

Interferometry and Fourier-Transform Spectroscopy (FTS) are important tools for characterization of coherent light sources. The ability to use these tools in combina-tion with extreme ultraviolet (XUV) radia-tion produced by high harmonic generation (HHG) provides a wealth of experimental capabilities in areas ranging from attosec-ond physics to high resolution coherent diffractive imaging. A general challenge is the need for a measurement setup that is interferometrically stable at the level of a wavelength fraction. We demonstrate XUV interferometry and FTS between 17 nm and 55 nm wavelength with an ultrastable common-path interferometer for femto-second, high-intensity laser pulses driving the HHG process. This approach enables the generation of fully coherent XUV pulses with less than 0.8 attosecond timing variation, a tunable time delay and a clean Gaussian spatial mode profile. We demon-strate the capabilities of XUV interferom-etry by performing spatially resolved FTS on a thin bilayer composed of titanium and silicon nitride.

Freek Ruesink1, Mohammad-Ali Miri2, Andrea Alù2, and Ewold Verhagen1

1 FOM Institute AMOLF2 University of Texas at Austin

On-chip photonic nonreciprocal compo-nents such as isolators and circulators provide highly desirable functionality for optical circuitry. A possible route towards violating reciprocity without a magnetic relies on a spatiotemporal modulation of the refractive index, which is straightforward-ly achieved in optomechanical systems. We derive the minimal requirements to create nonreciprocity in a wide class of optomechanical systems that involve a pair of optical modes coupled to a mechani-cal mode. These conditions highlight the importance of an appropriately tailored phase difference between the intra-cavity bias photons of the two optical modes. We utilize these principles to demonstrate up to 10 dB optical isolation at 1550 nm in a silica microtoroid optomechanical system. In line with our theoretical model, nonrecip-rocal transmission is preserved in the case of non-degenerate modes and also yields nonreciprocal parametric amplification. Our results open a route to creating a broad variety of nonreciprocal effects in optom-echanical systems in any electromagnetic and mechanical frequency regime, includ-ing optomechanical metameterials with topologically non-trivial properties.

P 51

Spatially resolved fou-rier-transform spectroscopy in the extreme ultraviolet

P 52

Nonreciprocity and magnetic-field free isolation based on optomechanical interactions

54 55

K. Saeedi1, N. Stavrias1, P.T. Greenland2, B. Redlich1, and B.N. Murdin3 1. FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.2. London Centre for Nanotechnology, University College London, London, United Kingdom.3. Advanced Technology Institute, University of Surrey, Guildford, United Kingdom.

Donor electrons in silicon have great prom-ise as building blocks for quantum infor-mation processing devices. The advantage of using such systems is the long orbital and spin coherence times. Bi is the deepest of the Group-V donors in silicon, shows narrow high lying orbital state linewidths. The lifetime of these orbital transitions sets a limit to the speed of the possible gate operations. We present results of the lifetime of the orbital excited states of Bi donors in Si, measured at cryogenic LHe temperature using pump-probe spectroscopy through THz excitation provided by FELIX. Resulting orbital lifetimes are consistent with those derived from the linewidths measured through FTIR. Using the pump-probe data as well as non-contact pho-to-conductive measurements, we were able to get an insight into the two-photon and thermal ionization processes.

Arthur La Rooij, Carla Sanna, David Davtyan, H.B. van Linden van den Heuvell, Robert J.C. Spreeuw Van der Waal-Zeeman Institute / Institute of Physics, University of Amsterdam

Lattices of ultracold atoms provide a versatile and tunable platform for the study of strongly interacting quantum many-body systems, including Hubbard and spin mod-els. Our quantum simulators are based on ultracold Rb-87 atoms trapped in nanofabri-cated magnetic lattices. This approach offers the great opportunity to design a variety of geometries and length scales, allowing the investigation of new physical regimes and many-body quantum phenomena arising from the increasing interactions in smaller and smaller lattices. We show a range of novel patterns nanofabricated on an atom chip, allowing the study of magnetic po-tentials for atom transport and localization, (super-)lattices with Kagome and honey-comb structure. The achievable resolution is of tens of nm with lattice parameters down to 200 nm. The flexibility of our approach is demonstrated by combining several struc-tures and even different lattices at interfaces on a single chip, including the realization of lattices with length scales varying continu-ously from 250nm up to 5um.

P 53

Life time of orbital excited states of Bismuth donors in silicon

P 54

Towards quantum simulation with ultracold atoms trapped in magnetic nanolattices

S. Greveling, M. Scholten, H. C. Jagers, and D. van OostenDebye Institute for NanoMaterials Science and EMMEPH, Utrecht University

Bose-Einstein condensation (BEC) of photons is fundamentally different than that of standard single component atomic Bose-Einstein condensates. First, because the phase of the electromagnetic field is in principle observable, whereas the phase of a quantum mechanical wave function is not. Second, because photons have an inherent polarization degeneracy. Here, we investigate the latter by in-situ imaging of the Stokes parameters of both the photon condensate and the thermal photons on a single shot basis.

R.U. Skannrup1, A.G. Boetes2, D. Niestadt1, J. Naber2, S.J.J.M.F. Kokkelmans1 and R.J.C. Spreeuw2

1Eindhoven University of Technology, Netherlands, 2University of Amsterdam, Netherlands

Magnetic trapping is a well-established technique for ground state atoms. We seek to extend this concept to Rydberg atoms. Rydberg atoms are important for current visions of quantum simulators that will be used in the near future to simulate and analyse quantum problems. Current efforts in Amsterdam rely on Rydberg atoms to be excited from a BEC in magnetic microtraps and to stay trapped after excitation. Rydberg atoms are atoms excited to high electronic states, with a spatial size compa-rable to the size of magnetic microtraps. The question is then whether Rydberg atoms are trappable in magnetic traps so tight that the magnetic field varies appreciably on length scales comparable to the atomic rms radius. Our research indicates that some Rydberg atoms will indeed remain trapped and shows how the magnetic trapping potential is affected by the finite size of Rydberg atoms.

P 55

Polarization of a photon Bose-Einstein condensate

P 56

Magnetic trapping of Rydberg atoms

56 57

Peter van der Slot1, Henry Freund2, Sandra Bie-dron2, Stephen Milton2 and Klaus-Jochen Boller1

1Mesa+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands2Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, USAE-mail: p.j.m.vanderslot@utwente.nl

A free-electron laser consists of relativistic electrons co-propagating with an optical wave through a static periodic magnetic field. The wavelength that is coherently amplified is set by the period and amplitude of the magnetic field and the energy of the electrons. Typically, assuming a period of a few centimeter for the magnetic field, an electron beam energy of more than 10 GeV is required to generate sub-nanometer wavelengths. The electron beam energy and amplitude of the magnetic field are direct tools to continuously vary the wavelength generated by the laser.

Here we describe a simulation code for free-electron lasers, called MINERVA, that uses a modal decomposition to describe the optical wave, solves the Newton-Lorentz equations to follow the electron trajectories through the combined optical and magnetic fields and solves the dynamic equations for the mode amplitudes driven by the elec-trons. Results for some existing free-elec-tron lasers will be presented.

Henk Snijders,1 J.A. Frey,2 J. Norman,3 M. P. Bakker,1 A. Gossard,3 J.E. Bowers, 3 M. P. van Exter,1 D. Bouwmeester,1,2 and W. Löffler1

1 Huygens-Kamerlingh Onnes Laboratory, Leiden University 2 Department of physics, University of California, Santa Barbara 3 Department of Electrical and Computer Engi-neering, University of California, Santa Barbara

Quantum dots (QDs) in high-quality optical micropillar cavities are a promising system for nanoscale quantum optics and information ap-plications. To entangle the photon polarization deterministically with the QD electron spin, one needs polarization degenerate cavities. Our QD-cavity system has the potential to generate high-fidelity spin-photon entangle-ment, because the cavity modes can be tuned to be nearly polarization degenerate, while the QD-cavity coupling strength is close to the strong coupling regime. The interaction of photons with the cavity-QED system is limited by a finite QD-cavity coupling strength. Here we show that, by polarization pre-and post-se-lection, we can restore perfect interaction and transform an incident coherent light beam into a stream of strongly correlated photons with g2(0) ~ 40 (Fig 1). By comparing the results with numerical simulations of the quantum master equation, we found first indications of photon-number sensitive Jaynes-Cummings physics in the weak coupling regime of cavi-ty-QED [1]. [1] Henk Snijders et al. arXiv:1604.00479

P 57

Modeling of Free-Electron Lasers

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Polarization-based purification of a single photon nonlinearity

Kevin Esajas, Artem Zapara, Sreekanth Mathavan, Klaus Jungmann, Lorenz Willmann, Steven HoekstraVan Swinderen Institute, University of Groningen

In our lab we operate a 4.0 m long trave-ling-wave decelerator, designed to decel-erate SrF molecules for a measurement of parity violation. The long interaction time of slow molecular beams allows for very sensitive tests of the Standard Model of particle physics. Operating at close to its maximum deceleration strength we can reduce the speed of SrF molecules from 290 to 120 m/s, thereby removing ~85% of their kinetic energy. Up to date this is the heaviest polar molecule slowed down to such low velocities.

We are aiming to decelerate even heavier polar molecules, such as BaF, a promising candidate both for the measurement of parity violation and to detect a possible electric dipole moment of the electron. For efficient deceleration of such heavy molecules, a lower initial speed is required. Therefore we are designing a cryogenic source that produces slow intense beams of polar molecules. In combination with the decelerator this enables slowing to 30 m/s, well below thermal velocity.

Slow molecular beams of heavy diatomic polar molecules

58 59

Sergei Sokolov1,2, Jin Lian1,2, Sanli Faez1, Silvain Combrie3, Alfredo De Rossi3, Allard P. Mosk1 1Utrecht University, Physics of Light in Complex Systems, The Netherlands2University of Twente, COPS, the Netherlands3Thales Research and Technology, France

Single photonic crystal nanocavities find many applications like optical switches, nonlinear devices and etc. When such cavities are optically coupled they form cou-pled resonator optical waveguides. Through optical coupling the transmission band with slow light is formed[1]. The slow group velocity is crucial for delay lines, optical buffers, memory storage and quantum com-munications[2].In this work we use the independent control of several nanocavites via local holographic laser heating, and study the optical coupling effects in the system. We control spatial temperature distribution in photonic crystal membranes[3], and align array of 3 cavities into hybridized state.

[1] J. Lian, S. Sokolov, E. Yϋce, S. Combrié,

A. De Rossi, A.P. Mosk, Opt.Lett., 40, 19 (2015)

[2] H. Takesue, N. Matsuda, E. Kuramochi,

W.J. Munro, M. Notomi, Nat. Commun., 4 (2013)

[3] S. Sokolov, J. Lian, E. Yϋce, S. Combrié.

G. Lehoucq, A. De Rossi, A.P. Mosk, Appl.Phys.Lett.,

106, 171113 (2015)

Nick Spook1, Harmen Sielcken2 and Paul Planken1 1Advanced Research Center for Nanolithograpy (ARCNL), University of Amsterdam2Advanced Research Center for Nanolithograpy (ARCNL), Utrecht University

We have investigated the linear optical properties of thin layers of Sn on CaF2 substrates in the wavelength range from 0.4 to 16 μm. The samples were prepared using thermal vapor deposition and have nominal film thicknesses of 10 through 90 nm. We observe a peak in the reflectivity that shifts to longer wavelengths as the effective layer thickness increases. We have studied the nanostructure of our samples using scanning electron microscopy (SEM) and atomic force microscopy (AFM). We found that the quantities of Sn deposited gave rise to the formation of island-like structures, the typi-cal diameters and heights of which increase with effective layer thickness. Based on the AFM measurements, we simulated the optical response of the samples with CST Microwave Studio.

P 59

Thermal tuning of photonic crystal cavity arrays

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Spectroscopic and microscopic studies of nanoscale Sn islands formed by thermal evaporation

Jeanine B.M.E. Stassen, J. Mandon, S.M. Cristescu, P. Brown, Frans J.M. Harren Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Nijmegen, the Netherlands.

Proton Transfer Reaction Mass Spectrome-try (PTR-MS) is used to detect trace quan-tities of volatile organic compounds in air. Its advantages are the high sensitivity and no need for sample preparation, as normal constituents of air such as nitrogen, oxygen and carbon monoxide are not detected.

In this study, PTR-MS was used to monitor the spoilage of lettuce in different types of modified atmosphere packaging. We aimed to identify biomarkers that indi-cate spoilage of the lettuce. Once these biomarkers have all been successfully determined, a sensor will be developed that will be placed onto commercially available fresh-cut and packaged lettuce. This way, retailers and consumers will be able to see if their produce is still fresh and safe to eat.

Gerrit W. Steen, 1,2 Sandra Drusovã,1,2 Elmar C. Fuchs,1 Adam D. Wexler,1 Herman L. Offerhaus2 1Wetsus, European Centre of Excellence for Sustainable water Technology2University of Twente

By recording differential absorbance spectra in the spectral range from 14000 to 9091 wavenumbers electrolytes can be identified and quantified [1]. This optical method has been integrated to enable on-line applications.

Another research line at Wetsus explores the possibilities of using fiber bragg grat-ings (FBG) in the field of hydrogeology. Optical sensors with FBG were designed for real-time monitoring of groundwater flow patterns and temperature.

[1] G. W. Steen, E. C. Fuchs, A. D. Wexler, H. L. Offer-

haus, Identification and quantification of 16 inorganic ions

in water by Gaussian curve fitting of Near-Infrared differ-

ence absorbance spectra, Applied Optics, 2015 in press

P 61

Using PTR-MS to monitor spoilage of lettuce

P 62

Optical sensors for identification and quantification of electorlytes and determation of grondwater flow speed

60 61

T. Madhu Trivikram, M.L. Niu, E.J. Salumbides, Wim Ubachs LaserLaB, VU Amsterdam

Accurate determination of level energies of the H2 electronic ground state X 1Σg

+, provides stringent tests on the most accurate ab initio molecular theory [1], that includes Born-Oppenheimer corrections, relativistic and QED effects. Doppler-free two-photon EF-X spectroscopy on vibrationally excited H2 [2], employing resonant ionisation to autoionising Rydberg states, resulted in X(ν=11) level energies with accuracies better than 0.002 cm-1. These values are in good agreement with, but are twice more ac-curate than the most advanced calculations.

In a parallel investigation, transition energies of the GK-X (1,0) band will be measured at 1-MHz accuracy. Narrowband 179-nm radiation is generated using a KBBF nonlinear crystal for the spectrosco-py. This will enable (in combination with [3]) an order-of-magnitude improvement of the dissociation energy D0, and will be 30 times more accurate than present theoretical uncertainty.

References:

[1] J. Komasa et al., J. Chem. Theory Comput. 7, 3105

(2011).

[2] M.L. Niu et al., J. Chem. Phys. 143, 081102 (2015).

[3] D. Sprecher et al., Mol. Phys. 111, 2100 (2013).

Y. Tao, S.J. Goh, P.J.M. van der Slot, H.J.M. Bastiaens, and K.-J. BollerLaser Physics and Nonlinear Optics group, MESA+ Institute for Nanotechnology,University of Twente, Enschede, 7500AE, The Netherlands

We present the first time dependent model for quasi-phase matching (QPM) in high-order harmonic (HH) generation. Using a one-dimensional model, we analyze the time-dependent, ultrafast wave vector balance to calculate the on-axis HH output vs. time, from which we obtain the time-integrated, overall output. Consider-ing, as an example, periodically patterned argon gas as may be provided with a grid in a cluster jet, we calculate the HH output during different time intervals within the drive laser pulse duration. We find that identifying a suitable single spatial period is not straightforward due to the complex plasma dynamics in HH generation. The maximum overall on-axis HH pulse energy is obtained when choosing the QPM period to phase match the HH generation at the leading edge of the drive laser pulse.

P 63

Tests of molecular theory from precision spectroscopies on H2

P 64

A temporal model for quasi- phase matching in high- order harmonic generation

V.T. Tenner, M.J.A. de Dood, M.P.E. van ExterHuygens-Kamerlingh Onnes Laboratory, Leiden University

Interaction between light waves and the free electrons in the surface of a metal give rise surface plasmons (SP). Such SPs can lead to highly confined fields on subwave-length scale. Due to the intrinsic properties of metals, the SP experience Ohmic losses. We fully compensate these losses with an optically pumped semiconductor gain layer and demonstrate SP-lasing on metal hole arrays (MHAs) with a hexagonal based lattice. In contrast to previous demonstra-tions of SP-lasers on square lattice MHAs, hexagonal based lattices exhibit richer physics inherent to the non-orthogonality of the unit vectors of the crystal. We char-acterize the polarization and spatial extend of the laser modes and we demonstrate mode selection by pump diameter tuning and we describe the results in terms of 2D distributed feedback laser theory.

Fig 1: Polarization and intensity of SP-laser emission

N. Valappol, E. A. Dijck, A. Mohanty, K. Jungmann, L. Willmann Van Swinderen Institute, University of Groningen

Light shifts permit the mapping of weak interaction effects onto the energy splitting between the magnetic sublevels. For the first time in a single trapped alkaline earth metal, Ba+ ion, light shifts in the 5d2D3/2-6p2P1/2 transition have been observed. The ion is in a hyperbolic Paul trap in Ultra High Vacuum in the 10−11mbar range. We demonstrate the Raman spectroscopic technique to precisely measure these light shifts. The measured light shifts in this transition is determined to be 0.16(3)GHz2 •1 /∆LS where ∆LS is the detuning of the light shift laser light from resonance. It is crucial for precise determi-nation of Atomic Parity Violation in the ion.

Fig. Scaling of light shifts for detuning from resonance of the

laser light

P 65

Surface plasmon lasing in hexagonal plasmonic crystals

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Light shifts measured in a single trapped Ba+ion

Detuning [GHz]40− 20− 0 20 40

Ligh

t Shi

ft [M

Hz]

10−

0

10

62 63

N.R. Verhart, P. Navarro, S. Faez and M. Orrit Molecular Nano Optics and Spin (MoNOS), Leiden Institute of Physics, Leiden University

Triplet states can be interesting for optical switching of molecular fluorescence as well as quantum experiments relying on the manipulation of spin states. However, the ground state of molecules is usually a singlet state. It is therefore interesting to study the intersystem crossing (ISC) rates between singlet and triplet states. We have measured the autocorrelation function of the fluorescence from single perylene molecules in an ortho-dichlorobenzene host matrix at cryogenic temperatures (1.2K) [1]. We observed two time scales in the autocor-relation function corresponding to ISC to two indistinguishable triplet states (TX and TY) and a third triplet state (TZ). By studying the power dependence of the correlation times and contrasts in the autocorrelation functions, we determine the ISC rates.

[1] Phys. Chem. Chem. Phys. 18 (2016) p17655-17659

Vanessa Verrina1, Paul Planken1

1ARCNL, Science Park 102, 1098XG, Amsterdam, V.Verrina@arcnl.nl

EUV lithography is a next-generation lithography technology using EUV wavelengths, currently 13.5 nm. An im-portant step in EUV light generation is the illumination and absorption of light by tin (Sn) droplets. In the process that leads up to the formation of the tin plasma, small tin particles are created with sizes in the micrometer and in the nanometer domain. In general, the absorption properties of metal particles with sizes on the order of the wavelength of the exciting light or smaller, are different from that of bulk metal. Our work focuses on the optical ab-sorption properties of small tin structures. We currently fabricate these structures on a substrate. To determine how they respond to the incident light, the transmittance and reflectance of the nanostructures were measured using an FTIR microscope. The results show that Au antennas with a 1.5 micron periodicity have resonance at ~1500 cm-1. Sn arrays don’t show any resonant behavior. SEM images show that this is because the Sn antennas are not continuous.

P 67

Intersystem crossing rates of single perylene molecules

P 68

Optical absorption at mid-IR wavelengths by metal nanostructures

Sjoerd N. Vogels, Jolijn Onvlee, Ad van der Avoird & Sebastiaan Y.T. van de MeerakkerMolecular and Laser Physics, Institute for Molecules and Materials, Radboud University

The interactions which take place when two molecules collide with each other are governed by their underlying poten-tial energy surfaces. At extremely low collision energies the collision dynamics are dominated by the wave-character of the colliding particles. The lower the collision energy in a scattering process, the smaller the amount of partial waves contributing to the scattering process. We developed a scattering apparatus which combines the Stark decelerator technique and a small scattering angle of 45 ° with the Velocity Map Imaging technique. The combination of these methods allows for obtaining collision energies below 15 cm-1 for nitric oxide molecules scattering with helium atoms. At such collision energies - close to the energetic threshold of rotational scatter-ing channels - scattering resonances can occur. At a scattering resonance a single or a few partial waves dominate the scattering process. Observing these scattering reso-nances and their influence on the angular distribution of scattered molecules can reveal the contribution of a single partial wave to the scattering dynamics1.

1Science 350, 787 (2015)

Y. Wang1, W. van de Water2, K. Liang3, W. Ubachs1 1 LaserLaB Vrije Universiteit2 Technische Natuurkunde, TU Eindhoven3 HUST Wuhan, China

Light scattering of gases provides informa-tion on the gas kinetics, collisional properties and internal relaxation in molec-ular species. At VU LaserLaB a laser-based spectrometer is built to sensitively measure the spontaneous light scattering profile of various gases at high resolution. After having studied atoms and atmos-pheric molecules, we moved toward larger molecules where internal vibrational and rotational relaxation play a role. SF6 gas is taken as a model system. In addition binary collision between SF6 and He atoms are investigated, where the He atoms play the role of collision partner and spectator, not significantly contributing to the scattering profile. The results are compared with a number of models, for the kinetic and for the hydrodynamic regime.

P 69

Observing scattering resonances in low-energy molecular collisions

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Rayleigh-Brillouin scattering in molecular gases and binary mixtures

64 65

Ted van der Weerden, Servaas Kokkelmans, Edgar Vredenbregt Coherence and Quantum Technology, Eindhoven University of Technology

Rydberg atoms have experimentally inter-esting properties such as strong long-range Van der Waals interactions and the dipole blockade effect. In optical lattices the block-ade effect ensures that only one Rydberg excitation per site is allowed, effectively creating a Rydberg crystal. We theoretically show that it is also possible for a one-di-mensional Rydberg crystal to spontaneously form in a random ensemble of atoms, e.g. a magneto-optical trap. This is done using an existing Monte Carlo model [1] to simulate the excitation dynamics inside the intersec-tion of two lasers for a two-step excitation scheme. With a blue-detuned laser for the upper transition, the first Rydberg excita-tion will occur after a relatively long time. That first Rydberg atom will then seed further Rydberg excitations, as the blockade effect shifts atoms at a certain distance into resonance. If two dimensions of the laser intersection are smaller than the blockade radius, a one-dimensional Rydberg crystal will form.

[1] C. Ates et al., Phys. Rev. A 76, 013413 (2007)

Gesa Welker1, Camiel van Efferen1, Fernando Luna2, Hedwig Eerkens1, Frank Buters1, Matthew Weaver2, Sven de Man1, Kier Heeck1, Michiel de Dood1, Wolfgang Löffler1 and Dirk Bouwmeester1,2

1 Leiden University 2 UC Santa Barbara

Quantum non-demolition measurements came up in the eighties [1] in connection to the design of interferometric gravitational wave detectors and have recently triggered interest again since several experimental groups succeeded in beating the standard quantum limit [2,3]. We present an optomechancial setup for evading classical measurement-induced backaction. Following a theoretical propos-al by Clerk et al. [4], we use a cavity with a movable end mirror (trampoline resonator) and an amplitude-modulated cavity drive. This enables us to measure one single mechanical quadrature of the resonator with in principle infinite precision. We aim to extend the setup so that also quantum measurement backaction coming from the particle nature of light can be evaded.

[1] Caves et al. Rev. Mod. Phys., Vol. 52, No. 2 (1980)

[2] Teufel et al. Nat. Nanotechnol. 4, 820-823 (2009)

[3] Anetsberger et al. Phys. Rev. A 82, 061804 (2010)

[4] Clerk et al. New J. Phys. 10, 095010 (2008)

P 71

Spontaneous formation of one-dimensional Rydberg crystals in an ultracold gas

P 72

Backaction evasion with an optomechanical trampoline resonator cavity

Tom A.W. Wolterink, Ravitej Uppu, Klaus-J. Boller, and Pepijn W.H. PinkseMESA+Institute for Nanotechnology, University of Twente, The Netherlands

We investigate the propagation of quantum states in massively multichannel networks. The networks consists of an array of five thousand nearest-neighbour coupled silicon nitride waveguides. The control is achieved using adaptive phase modulation of the light incident in every waveguide. In this way we realize massively multichannel linear optical networks with programmable quantum correlations, without tuning the network itself. We will report on the pro-gress of this research and show first results.

Ravitej Uppu, Tom A.W. Wolterink, Tristan B.H. Tentrup, and Pepijn W.H. Pinkse MESA+ Institute for Nanotechnology, University of Twente, The Netherlands

Beam splitters are primitive components in any linear optical quantum network. When two indistinguishable single photons are incident on the two input ports of a lossless symmetric beam splitter, they both exit the beam splitter through the same output port. This is the well-established Hong-Ou-Man-del (HOM) interference. With the advent of complex wavefront shaping of light in a multiple scattering medium, programmable beam splitters for coherent light have been demonstrated. These beam splitters support any arbitrary phase relation between the two output ports and hence are asymmetric. Furthermore, the light lost due to the partial control of the incoupled light in the scat-tering medium results in lossy asymmetric beam splitters. Here, we derive the output states of these beam splitters and discuss the dependence of the HOM visibility on the phase difference between the output ports. We discuss these calculations in the context of our recent experimental measurements.

P 73

Control of light in massively multichannel networks

P 74

Quantum optics of lossy asymmetric beam splitters

66 67

Tom A.W. Wolterink, Ravitej Uppu, Sebastianus A. Goorden, Boris Škorić, Allard P. Mosk, and Pepijn W.H. Pinkse MESA+ Institute for Nanotechnology, University of Twente, The Netherlands

We demonstrate quantum-secure asym-metric communication using an optical physical unclonable function (PUF) as key. PUF-enabled asymmetric quantum com-munication (PEAQC) allows for the secure transmission of messages to any receiver in an asymmetric fashion. Illumination of a multiple-scattering key with light that contains fewer photons than spatial degrees of freedom allows authentication of the key and communication of a message, while quantum-physical principles prohibit digital emulation. As the method is based on quan-tum-secure authentication it does not rely on any stored secrets, the receiver is inherently authenticated and the reception of a message can easily be verified by the sender.

S.H.W. Wouters, G. ten Haaf, T.C.H de Raadt, O.J. Luiten, P.H.A. Mutsaers, and E.J.D. VredenbregtCoherence and Quantum Technology group, Eindhoven University of Technology

Photo-ionization is applied to a laser cooled and compressed atomic rubidium beam in order to generate a high brightness ion beam. When focused, this ion beam can be used to image and edit integrated cir-cuits at the nano-scale which is important for the ongoing reduction of feature sizes in the semiconductor industry.Experiments have shown that an atomic beam brightness in excess of 106 A/(m2 sr eV) can be achieved with a flux equivalent to 500 pA in a compact magneto-optical compressor which should be sufficient to generate ion spots of 1 nm. Currently, photo-ionization experiments are being carried out that aim at ionizing the majority of the atoms within a small longitudinal range in order to minimize the longitudinal energy spread. The two step ionization setup uses a tightly focused excitation laser beam and a powerful blue laser coupled to a build-up-cavity.

P 75

PUF-enabled asymmetric quantum communication

P 76

Two step photo-ionization of a la-ser cooled and compressed thermal atomic beam for use in a focused ion beam

E.C.I. van der Wurff & H.T.C. StoofInstitute of Theoretical Physics, University Utrecht

After the creation of condensates of qua-siparticles like magnons and exciton-po-laritons, the first condensate of photons was created in the Weitz group in Bonn in 2012. This new experimental set-up provides new experimentally accessible possibilities, as opposed to ultra-cold atom-ic condensate clouds. We will first try to elucidate the technical details of the experi-ment. Furthermore, we discuss some exam-ples of many-body phenomena that could be encountered. Both phenomena that are well known from the atomic condensates and phenomena that could be measured for the first time in this new condensate shall be discussed.

J. Scheers1,2, P. Mazzella1,3, R. Hoekstra1,4 , O. O. Versolato1, and W. Ubachs1,2 1 ARCNL, Amsterdam2 Vrije Universiteit, Amsterdam3 University of Amsterdam, University of Groningen

The environment of a laser-produced plasma source of extreme ultra-violet light provides many opportunities for laser-spectroscopic investigations. In particular, laser-induced fluorescence studies of SnI,II will help shed light on their local densities and velocities. Molecular species SnHx (x=1-4) are also expected to form as a result of plasma formation in a hydrogen-rich environment. In-situ spectroscopic studies of the internal rovibrational states of SnH give access to local temperatures. Detailed plans and the latest results of these studies performed at ARCNL using a tunable pulsed dye laser setup will be presented. Such measurements are of interest for the development of diag-nostic techniques of tin mitigation in EUV sources.

P 77

Many-Body phenomena in a condensate of light

P 78

Spectroscopic studies on Sn plasma

68 69

NOTES

WorkgroupsConference center

De Werelt Lunteren

70 71

Workgroups

AMSTERDAM (FOM Institute AMOLF)----------------------------------------------------------------------------------------------------------------prof. dr. H.J. Bakker Ultrafast Spectroscopy----------------------------------------------------------------------------------------------------------------prof. dr. L. Kuipers NanoOptics----------------------------------------------------------------------------------------------------------------prof. dr. A. Polman Photonic Materials----------------------------------------------------------------------------------------------------------------prof. dr. A.F. Koenderink Resonant Nanophotonics----------------------------------------------------------------------------------------------------------------dr. E. Verhagen Photonic Forces----------------------------------------------------------------------------------------------------------------dr. Y. Rezus Biomolecular Photonics----------------------------------------------------------------------------------------------------------------dr. B. Ehrler Hybrid Solar Cells----------------------------------------------------------------------------------------------------------------dr. E. Garnett Nanoscale Solar Cells----------------------------------------------------------------------------------------------------------------

AMSTERDAM (Advanced Research Center for Nanolithography ARCNL)----------------------------------------------------------------------------------------------------------------prof. dr. A.M. Brouwer Nanophotochemistry----------------------------------------------------------------------------------------------------------------prof. dr. P. Planken EUV Targets----------------------------------------------------------------------------------------------------------------prof. dr. R. Hoekstra EUV Plasma Dynamics----------------------------------------------------------------------------------------------------------------dr. O. Versolato Atomic Plasma Processes----------------------------------------------------------------------------------------------------------------dr. N. Ottoson EUV Photoemission----------------------------------------------------------------------------------------------------------------dr. S. Witte EUV Generation and Imaging----------------------------------------------------------------------------------------------------------------

Workgroups

AMSTERDAM (University of Amsterdam)----------------------------------------------------------------------------------------------------------------prof. dr. T. Gregorkiewicz Opto-electronics Materialsdr. K. Dohnalova----------------------------------------------------------------------------------------------------------------dr. R.Sprik Soft matter physics waves in complex media.----------------------------------------------------------------------------------------------------------------prof. dr. H.B. van Linden van den Heuvell Quantum Gases. Atom Optics. Quantum information.prof. dr. G.V. Shlyapnikovdr. R.J.C. Spreeuwdr. N.J. van Druten Rydberg atoms. Atom chipsdr. T.W. Hijmans ----------------------------------------------------------------------------------------------------------------prof.dr. F. Schreck Ultracold ground-state Molecules. Quantum gas Microscopy. Quantum simulation. Atom Lasers----------------------------------------------------------------------------------------------------------------prof. dr. J.T.M. Walraven Trapped ions. Quantum gases.dr. R. Gerritsma----------------------------------------------------------------------------------------------------------------

AMSTERDAM (VU University)----------------------------------------------------------------------------------------------------------------prof. dr. W. Ubachs Frequency metrology and precision spectroscopy of prof. dr. K.S.E. Eikema atoms and molecules for probing fundamental physics, dr. W. Vassen testing the Standard Model, variation of fundamental dr. H.L. Bethlem constants, the proton-size puzzle, quantum gases and dr. S. Knoop BEC, cold molecules, ultrafast lasers and frequency dr. E.J. Salumbides combs, X-ray generation and lensless imaging, cavity ring down detection, atmospheric light scattering, fiber-optic time and frequency transfer.----------------------------------------------------------------------------------------------------------------

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Workgroups

AMSTERDAM (VU University)----------------------------------------------------------------------------------------------------------------prof. dr. J.F. de Boer Biophotonics, biophysics, Optical Coherence prof. dr. M.L. Groot. Tomography, spectroscopy, non-linear, CARS, SRS prof. dr. D. Iannuzzi: and Raman microscopy, , ultrafast spectroscopy, dr. F. Ariese optomechanics in Life Sciences, High Precision dr. S. Witte Experiments on Surface Forces, Table-Top Dark Energy. ----------------------------------------------------------------------------------------------------------------

DELFT (University of Technology)----------------------------------------------------------------------------------------------------------------prof. dr. H. P. Urbach Near and far field optical inspection techniquesdr. S. Pereira Optical designdr. A.J. L. Adam Optical lithographydr. F. Bociort Optical nanostructures and metamaterials.dr. N. Bhattacharya Thin films Terahertz imaging & spectroscopy Applications of femtosecond frequency comb lasers in length measurement, breath analysis and gas detection----------------------------------------------------------------------------------------------------------------prof. dr. ir. R. Hanson Quantum science in the solid state, quantum. ----------------------------------------------------------------------------------------------------------------Dr. S. Gröblacher Quantum optomechanics----------------------------------------------------------------------------------------------------------------Dr. T.H. Taminiau Quantum information with defect color centers----------------------------------------------------------------------------------------------------------------

EINDHOVEN (University of Technology----------------------------------------------------------------------------------------------------------------pdr. ir. G.J.H. Brussaard Ultra cold plasma’s, Rydberg atoms, bright ion and dr. ir. S.J.J.M.F. Kokkelmans electron beams, atom optics, nanostructures by atom prof. dr. K.A.H. van Leeuwen lithography, Compact (laser-driven) electron prof. dr. ir. O.J. Luiten accelerators; generation of collective radiation (THz to dr. ir. P.H.A. Mutsaers XUV), including FEL physics; femtosecond-pulse physics, dr. ir. E.J.D. Vredenbregt cold atomic interactions, quantum gasesprof. dr. J. Gómez Rivas DIFFER----------------------------------------------------------------------------------------------------------------

Workgroups

ENSCHEDE (Twente University)----------------------------------------------------------------------------------------------------------------prof. dr. K.J. Boller Laser physics and nonlinear optics dr. H. M. J. Bastiaens Integrated laser physics and nonlinear opticsdr. P.J.M. van der Slot High-harmonic generation Free-electron lasers. ----------------------------------------------------------------------------------------------------------------prof. dr. J.L. Herek Biomolecular control, field shaping, coherent dr. ir. H.L. Offerhaus Icontrol,nonlinear/vibrational.dr. ir. A. Huijser Spectroscopy/microscopy, nanophotonics, plasmonic structures, near-field probe microscopy.dr. S. Garcia-Blanco Integrated Opticsdr. M.L Bennink Nano biophysics, genomic, proteomics, spectroscopy.dr. H. Kangerdr. R. Kooyman dr. I. Segers-Nolten ----------------------------------------------------------------------------------------------------------------prof.dr.ir. W. Steenbergen Biomedical photonic imaging, tissue imaging photo prof.dr. L.F. de Geus-Oei acoustic and acoustic-optic imaging and speckle based dr. S. Manohar perfusion imaging.dr.ir. I.M. Vellekoop----------------------------------------------------------------------------------------------------------------prof. dr. L.W.M.M. Terstappen Medical cell biophysics, (non-)linear Raman dr. C. Otto spectroscopy and microscopy, Correlative Raman- dr. R. Schasfoort electron microscopy, nano-particle micro-spectroscopy, dr. M. Beck surface plasmon diagnostics and spectroscopy and imaging, medical micro-devices, point-of-care diagnostics, electro-opto-fluidics----------------------------------------------------------------------------------------------------------------prof. dr. W.L. Vos Photonic crystals, scattering and localization. dr. P.W.H. Pinkse Nanophotonics and Quantum optics----------------------------------------------------------------------------------------------------------------

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Workgroups

GRONINGEN (University of Groningen) ----------------------------------------------------------------------------------------------------------------dr. M.S. Pchenichnikov Optical Condensed Matter Physics.dr. R.I. Tobey Multidimensional femtosecond optical spectroscopy.----------------------------------------------------------------------------------------------------------------prof. dr. J. Knoester Theory of Condensed Matterdr. T. L.C. Jansen dr. V.A. Malyshev ----------------------------------------------------------------------------------------------------------------Dr. W.R.Browne Molecular Systems and Interfaces----------------------------------------------------------------------------------------------------------------dr. G. Palasantzas Nanoscale surface physics and Casimir forces----------------------------------------------------------------------------------------------------------------prof. dr. A. van Oijen Single-Molecule Biophysics & Molecular Microscopydr. T.M. Cordes----------------------------------------------------------------------------------------------------------------prof. dr. ir. C.H. van der Wal Physics of Quantum Devices.----------------------------------------------------------------------------------------------------------------prof. dr. J.C. Hummelen Chemistry of (bio)molecular materials and devices & FOM focus group Next generation organic photovoltaics----------------------------------------------------------------------------------------------------------------prof. dr. M. A. Loi Photophysics and OptoElectronicsdr. L.J.A. Koster----------------------------------------------------------------------------------------------------------------prof. dr. J. Ye Device Physics of Complex Materials---------------------------------------------------------------------------------------------------------------- prof. dr. ir. R. Hoekstra Atomic and molecular processes. Quantum dr. T. Schlathölter interactions and structural dynamics. Radiation damage in biomolecular systems. Highly-charged ion physics.----------------------------------------------------------------------------------------------------------------prof. dr. K. Jungmann Precise control and spectroscopy of ions.prof. dr. H. Wilschut Atoms and molecules, for tests of fundamentaldr. L. Willmann interactions and symmetries.dr. C.J. G. Onderwaterdr. S. Hoekstra----------------------------------------------------------------------------------------------------------------

Workgroups

LEIDEN (Leiden University)----------------------------------------------------------------------------------------------------------------prof.dr. D. Bouwmeester Quantum entanglement. Optomechanics,dr. M.J.A. de Dood semiconductor quantum physics (spintronics). prof.dr. E.R. Eliel Photonic crystals. Nanophotonics. Plasmonicsprof. dr. M.P. van Exterprof. dr. J.P. Woerdman----------------------------------------------------------------------------------------------------------------prof. dr. G. Nienhuis Optical traps. Light forces. Quantum information----------------------------------------------------------------------------------------------------------------prof. dr. E.J.J. Groenen Single-molecule physics.prof. dr. M. Orrit Electron Paramagnetic Resonancedr. P. Gast dr. M.I. Huber----------------------------------------------------------------------------------------------------------------prof.dr. H.V.J. Linnartz Laboratory astrophysics

----------------------------------------------------------------------------------------------------------------NIJMEGEN (Radboud University)----------------------------------------------------------------------------------------------------------------prof. dr. D.H. Parker Laser physics, molecular photodissociation, dr. F.J.M. Harren atmosheric processes, trace gas detection, medical and biological applicationsdr. S.Y.T. van de Meerakker Cold and controlled collisions----------------------------------------------------------------------------------------------------------------prof. dr. Th. Rasing Time-resolved laser spectroscopy, nanomagnetism, prof. dr. A. Kirilyuk spin- and magnetization dynamics, atomic clusters, dr. A.V. Kimel THz spectroscopy, nonlinear optics----------------------------------------------------------------------------------------------------------------prof. dr. ir. G.C. Groenenboom Molecular interactions and light-induced processes.dr. H.M. Cuppen Mobility in solid molecular materialsprof. dr. ir. A. van der Avoird ----------------------------------------------------------------------------------------------------------------prof. dr. W.L. Meerts Biomolecular structure, Molecular and atmospheric Physics, THz generation, detection and applicationsdr. A.M. Rijs to biomolecules and bio-mimetics, Free Electron Laser.

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Workgroups

----------------------------------------------------------------------------------------------------------------dr. A.F.G. van der Meer FEL physics, generation and application of dr. B. Redlich infrared/THz radiation.----------------------------------------------------------------------------------------------------------------prof. dr. J. Oomens Molecular physics. infrared ion spectroscopy and dr. J.M. Bakker structure, conformation selective spectroscopy, dr. G. Berden mass spectrometry, biomolecules, metal clusters, astrochemistry, coordination chemistry----------------------------------------------------------------------------------------------------------------

UTRECHT (Utrecht University)----------------------------------------------------------------------------------------------------------------prof. dr. P. van der Straten Laser manipulation of atoms, Bose-Einstein condensation, Atom optics.----------------------------------------------------------------------------------------------------------------dr. D. van Oosten Cold atom nanophotonics.----------------------------------------------------------------------------------------------------------------prof.dr. A.P. Mosk -----------------------------------------------------------------------------------------------------------------prof.dr.ir. H.T.C. Stoof Dynamics of Bose-Einstein Condensates, Quantum Effects in Degenerate Fermion and/or Boson gases.---------------------------------------------------------------------------------------------------------------- dr. R.A. Duine Spintronics. prof.dr. H.V.J. Linnartz Laboratory astrophysics----------------------------------------------------------------------------------------------------------------

NOTES

schuine kaderlijn 4º

This meeting is organized under the auspices of the NNV-Section

Atomic, Molecular and Optical Physics, with the financial support

of the Dutch Science Foundation and the Foundation FOM.

Design

Sophie van Kempen, bno

www.visueleidentiteit.com

This program is compiled by Dries van Oosten & Ronald Hanson