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The University of Tokyo, The University of Tokyo, The Institute For Solid State The Institute For Solid State Physics Physics Yasuhiro Yasuhiro Iye Iye November 11, 2005 University Lecture Science of Material Lecture 6 What is Condensed Matter Physics? Lecture 6 What is Condensed Matter Physics? Lecture 7 Lecture 7 Quantum Mechanics and Artificial Quantum Mechanics and Artificial Materials Materials -- -- High High - - tech and the State tech and the State - - of of - - the the - - art Physics art Physics Lecture 8 Lecture 8 Atom Control and Quantum Control Atom Control and Quantum Control -- -- Nano Nano - - science and Quantum Information science and Quantum Information Lecture 9 Lecture 9 Diverse Matter and Physical Properties Diverse Matter and Physical Properties The figures, photos and moving images with ‡ marks attached belong to their copyright holders. Reusing or reproducing them is prohibited unless permission is obtained directly from such copyright holders.

-- High-tech and the State-of-the-art Physics Lecture 8 Atom … · 2008. 6. 4. · Semiconductor (ULSI) A prediction of Gordon Moore that the number of transistors (degree of integration)

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  • The University of Tokyo, The University of Tokyo, The Institute For Solid State The Institute For Solid State

    PhysicsPhysicsYasuhiro Yasuhiro IyeIye

    November 11, 2005University LectureScience of Material

    Lecture 6 What is Condensed Matter Physics?Lecture 6 What is Condensed Matter Physics?Lecture 7 Lecture 7 Quantum Mechanics and Artificial Quantum Mechanics and Artificial

    MaterialsMaterials---- HighHigh--tech and the Statetech and the State--ofof--thethe--art Physicsart Physics

    Lecture 8Lecture 8 Atom Control and Quantum ControlAtom Control and Quantum Control----NanoNano--science and Quantum Information science and Quantum Information

    Lecture 9Lecture 9 Diverse Matter and Physical PropertiesDiverse Matter and Physical Properties

    The figures, photos and moving images with ‡ marks attached belong to their copyright holders. Reusing or reproducing them is prohibited unless permission is obtained directly from such copyright holders.

  • Review of Lecture 6 (1)Review of Lecture 6 (1)

    Story about scale.Story about scale.Modern civilization and physics.

    Personal computers, cellular phones, satellite communications, GPS, and MRI.Semiconductors, magnetic bodies, dielectric, liquid crystals, gels, superconductors.

    Condensed matter physics is the field of physics.Matter and materials.Materials science and materials engineering.Incorporation of the concept with elementary particle physics.The hierarchy structure in the physical world. ⇒ emergent properties.Diversity in matter and physical properties.

  • Review of Lecture 6 (2)Review of Lecture 6 (2)Quantum mechanics and atomic structure.

    Energy level in atoms ⇒ shell structure ⇒ periodic law.The energy scale ~eV in the outermost shell is the most essential to the properties of the element.

    The existing forms of matter.Energy versus entropy ⇒ phase transition.

    Agglutination mechanism and crystal structure in atom.Crystal structure Crystal structure ⇒⇒ XX--rayray((electron beam, neutron beam) electron beam, neutron beam) diffraction.diffraction.The bonding force of atoms: Van der Waal bonding, ion bonding, covalent bonding, metal bonding, hydrogen bonding.

    ⇒ Diversity of matter and physical properties. (Lecture 9)

  • TodayToday’’s Topicss Topics

    Overview of quantum mechanicsOverview of quantum mechanicsQuantum interferenceQuantum interferenceArtificial materials in Artificial materials in mesoscopicmesoscopicsystemssystemsQuantum conductionQuantum conduction

  • Overview of Quantum MechanicsOverview of Quantum Mechanics

  • Quantum MechanicsQuantum MechanicsTheoretical description of behaviors in microscopic systems.

    Structure of atoms and molecules.The behavior of an electron in a solid state.Visible radiation and matter.

    Particle properties: discreteness and separatenesWave properties: superposition and interference

    Light: possesses both wave and particle properties.Electron: particle and wave at the same time.

    The expressions such as “particle” and “wave” used to refer to everyday phenomena (classical mechanics) is now considered just an analogy that contributes to the phenomena relevant to quantum mechanics.

  • In Quantum Mechanics, a Particle also Behaves as a Wave

    de Broglie wavelength of electron accelerated at 100V:

    mEpm

    pE 22

    2

    =⇒=

    m1023.1106.11001091.02

    1062.62

    10

    1930

    34

    −−

    ×=×××××

    ×=

    ==mEh

    phλ

    nm12.0=λ

    de Broglie wavelength:ph

    =λMomentum

    de Broglie wavelength in classical particles, e.g., tennis ball is extremely short.

  • Quantum MechanicsQuantum Mechanics

    Time evolution of a wave function follows Schrodinger’s equati

    ),,,()(2

    ),,,( 22

    2

    2

    2

    22

    tzyxrVzyxm

    tzyxdtdi ψψ ⎟⎟

    ⎞⎜⎜⎝

    ⎛+⎟⎟⎠

    ⎞⎜⎜⎝

    ⎛∂∂

    +∂∂

    +∂∂

    −=h

    h

    The existence probability of a particle is given by: 2),,,( tzyxψ

    The state of a particle is described by a wave function: ),,,( tzyxψ,,( zyxψ

    Linear equation ⇒ superposition principle2121, ψψψψ +⇒ ⇒ Quantum interference

  • Uncertainty RelationUncertainty RelationThere is uncertainty relation between position and momentum for particle in quantum mechanics. h≥Δ⋅Δ px

    x k

    f x( ) a k( )

    2πk0

    e ik x0

    0 k

    デルタ関数

    フーリエ変換

    Defined momentum

    Plane wave

    0kp h=

    xikex 0)( =ψ

    フーリエ変換

    x k

    Δx Δk~ /1 Δx

    Wave packet∑=

    k

    ikxekcx )()(ψ

    Delta functionFourier transformation

    Fourier transformation

  • QuantumQuantum--mechanical State and mechanical State and Measured ValueMeasured Value

    The existence probability of a particle can be obtained by:2),,,( tzyxψ

    The exact point of existence can be determined by measuring the position of the particle.

    a aEach physical quantity has corresponding operator:

    eigenfunction and eigenvalue of operator.

    The state in quantum mechanics is described in “wave function”, in other words “Hilbert space”, i.e., state vector in abstract space.

    λψψ =Linear algebra a

    固有ベクトルの場合

    a=λa

    Eigenvector

  • Quantum Mechanical MeasuringQuantum Mechanical MeasuringIn general, quantum mechanics can give probability distribution of measurements obtained by repeated measurement of the “same state” physical quantity but, it cannot give the probability distribution of measured values of different and individual states.

    Measurement determines the quantum state in a single eigenstateof physical quantity ⇒ “contraction of the state”

    The observation problem and interpretation problem of quantum mechanics

    Time evolution in Schrodinger’s equation and the contraction of wave function by measurement.

    The most common interpretation in quantum mechanics: Copenhagen interpretation.

  • Characteristic Phenomena in Characteristic Phenomena in Quantum MechanicsQuantum Mechanics

    Tunnel effectTunnel effectParticle can pass through Particle can pass through a potential barrier, a potential barrier, something that is something that is inconceivable in inconceivable in classical mechanics. classical mechanics. ?

    Quantum interference Quantum interference effecteffect

    SuperpositioningSuperpositioning of of different paths.different paths.⇒⇒ quantum quantum interference.interference.

    IyeIye, Yasuhiro., Yasuhiro. Alice no Alice no RyoshiRyoshi RikigakuRikigaku.. InIn Parity.Parity. Tokyo: Maruzen, 2006.Tokyo: Maruzen, 2006.

  • Quantum InterferenceQuantum Interference

  • Light Wave InterferenceLight Wave InterferenceThe double-slit experiment by Young. (1805)

    Image of interfering waves as light passes through each slit.

    In phase

    Opposite phase

    qdIncident wave

    Diffracted wav

    q

    ( )⎩⎨⎧

    +=

    打ち消し合い

    強め合い

    λλ

    θ21

    sinn

    nd Intensifying

    Canceling

    出典確認中

  • For Classical ParticlesFor Classical Particles

    )()()( LRtotal yPyPyP +=

    Probability of bullets hitting the wall:=probability of bullets hitting the wall

    through the right slit.+probability of bullets hitting the wall

    through the left slit.

    Single slit

    A double slit

    IyeIye, Yasuhiro., Yasuhiro. Alice no Alice no RyoshiRyoshi RikigakuRikigaku.. InIn Parity.Parity. Tokyo: Maruzen, 2006.Tokyo: Maruzen, 2006.

  • The Incident WaveThe Incident Wave

    P y( )

    y

    Interference pattern

  • Particles in Quantum MechanicsParticles in Quantum Mechanics

    LRtotal Ψ+Ψ=Ψ

    Wave function=Wave function for particles passing thorough the right slit.+Wave function for particles passing through the left slit.

    Probability=|Wave function|2

    *LRL

    *R

    2L

    2R

    2LR

    2total

    ΨΨ+ΨΨ+Ψ+Ψ=

    Ψ+Ψ=Ψ

    Quantum interference term

  • Electron InterferenceElectron Interference

    Dr. Akira Sotomura(Advanced Research

    Laboratory, Hitachi, Ltd.)

    Electron source

    Electron

    DetectorElectron beam

    bi pri sm

    Figure 3. A double-slit experiment of electrons:Electron beam biprisms are used to replace slits. The experiment was so difficult to perform that people used to think that it could berealized only in one’s mind and not in reality.

  • The DoubleThe Double--slit Experiment of Electron slit Experiment of Electron (Dr. Akira (Dr. Akira SotomuraSotomura))

  • Electron InterferenceElectron Interference

    Electrons individually reach the screen.

    Interference pattern appears.

    Clear evidence for an electron’s wave properties.

    Dr. Akira Sotomura(Advanced Research

    Laboratory, Hitachi, Ltd.)

    Electron source

    Electr on b eam b ip r is m

    Electron

    Detector ‡

  • AharonovAharonov--BohmBohm Effect (AB Effect)Effect (AB Effect)

    eh

    de

    de

    de

    de

    ==

    ⋅=⋅=

    ⋅−⋅=Δ

    ∫∫

    ∫∫

    00

    loop

    RL

    2

    )()(

    )()(

    φφφπ

    θ

    SrBrrA

    rrArrA

    hh

    hhThe magnetic field(vector potential)changes the phase of the electron. ∫⇒

    ⋅ rrA deie

    )(hψψ

    Electron source

    Electron beam biprism

    Coil

    Phase difference

    出典確認中

  • How Large Can a Particle Be in Order How Large Can a Particle Be in Order to Interfere?to Interfere?

    C60

    A.ZeilingerVienna University of Technology ‡

  • Same Observation for LightSame Observation for Light

    Photomultiplier tube catches faint light.

    A single photon can be detected.

    Light is more likely to be regarded as a wave but it has particle properties as well.

    ⇒ photoelectric effect

    http://crd.search.yahoo.co.jp/MMSIMG/Q=%B8%F7%C5%C5%BB%D2%C1%FD%C7%DC%B4%C9/U=http%3A%2F%2Fwww.matsusada.co.jp%2Fproduct%2Fopt%2Fpmt3852hd%2Fimg%2Fpmt3852hd.jpg/O=7b7b149948a5fdf8/P=84/C=ckh59tsuor7ho&b=2/F=f/I=yahoojp/T=1129680208/*-http://www.matsusada.co.jp/product/opt/pmt3852hd/img/pmt3852hd.jpg

  • Topics we have covered up to now only deal Topics we have covered up to now only deal with quantum interference in a vacuum state.with quantum interference in a vacuum state.Do electrons in matter perform quantum Do electrons in matter perform quantum interference too?interference too?Quantum interference properties: coherence.Quantum interference properties: coherence.DecoherenceDecoherence makes for a loss of coherence in makes for a loss of coherence in the system.the system.

  • Artificial Materials and Artificial Materials and MesoscopicMesoscopic SystemsSystems

  • The Microscopic Universe1 m10-3 m10-9 m10-12 m 10-6 m

    1 pm

    Picometer1 nm

    Nanometer1 μm

    Micro-meter(micron)

    1 mm

    Millimeter

    Optical microscope

    Electron microscope

    Scanning probe microscope

    O-157

    Needle hole and hum

    an hair

    Bacteria

    Wavelength of visible light

    Virus

    Size of atom

    Size of atomic nucleus

  • The The MesoscopicMesoscopic SystemSystem

    Macroscopic scale

    Microscopic scale

    Mesoscopic scale

    It is an intermediate scale between microscopic and macroscopic systems.

  • 12 inch (30 cm)

    Silicon wafer

    MicroMicro--processing for processing for Semiconductor DevicesSemiconductor Devices

    The first transistor invented by Bell Labs in the U.S.A. (1946)

    50 yearsPicture removed due tocopyright restrictions

  • Magnetic Recording MediaMagnetic Recording Media

    Hard discMO disc

    Information recording method that takes advantage of magnetization directions in a small magnetic body.Recording unit (bit) of a high capacity HD is:0.1mm×1mm

    Track

    One bit interval

    Disk

    Interval of tracks

    The latest HDD is composed of 2,700 tracks per width 1mm and 28,000 recording bits per length 1mm in circumferential direction. For higher capacity, the track density is increased because there ismore room allowed in filling out the tracks.

    28,000 recording bits per length 1mm.

    2,700 tracks per width 1mm.

  • Silicon Silicon MonocrystalMonocrystal ⇒⇒ Wafer Wafer ⇒⇒Super LSISuper LSI

    Cutting out of the monocrystal. Wafer

    Super LSI (Large Scale Integration)

    Micro-processing

    http://www.um.u-tokyo.ac.jp/DM_CD/DM_CONT/SILICON/SILI07.JPGhttp://www.um.u-tokyo.ac.jp/DM_CD/DM_CONT/SILICON/SILI22.JPGhttp://www.um.u-tokyo.ac.jp/DM_CD/DM_CONT/SILICON/SILI08.JPGhttp://www.um.u-tokyo.ac.jp/DM_CD/DM_CONT/SILICON/SILI19.JPG

  • UltraUltra--large Scale Integration large Scale Integration Semiconductor (ULSI)Semiconductor (ULSI)

    A prediction of Gordon Moore that the number of transistors (degree of integration) on a semiconductor chip doubles every one and half to two years.

    It is clear that there is a limit to the micro-processing technique because semiconductor devices have already reached submicron scale (less than1μm) .

    Moore’s law

    Chip area

    Transistor amount (10,000)

    Smallest processing size (gate length) (nm)

    Clock frequency (MHz)

    Figure 1. Development of LSI (Microprocessor)Year

    http://crd.search.yahoo.co.jp/MMSIMG/Q=%A5%E0%A1%BC%A5%A2%A4%CE%CB%A1%C2%A7/U=http%3A%2F%2Fwww.fsas.co.jp%2Fseeds%2Fwebs%2F0401_03%2Fimages%2Ft_20040101_1.gif/O=ef3675b6dfa5b77a/P=218/C=ckh59tsuor7ho&b=2/F=f/I=yahoojp/T=1129686290/*-http://www.fsas.co.jp/seeds/webs/0401_03/images/t_20040101_1.gif

  • Size of the system Land

    The lengths that are characteristic of physical phenomenade Broglie wavelength

    Free mean pathPhase relaxation length

    The The MesoscopicMesoscopic SystemSystem

    The behaviors are different from those of a microscopic system; strong effects of quantum mechanics can be observed.

    Region of submicron-scale

    φL

  • Conditions Necessary for Conditions Necessary for MesoscopicMesoscopicPhysics and Physics and NanoscienceNanoscience

    Artificial materialsMicro-processingExtreme environments (extreme low temperatures and strong magnetic fields)High-sensitivity, high-resolution, and high-accuracy measurements

  • Artificial Artificial SuperlatticeSuperlattice

    Dr. Leona Esaki (1972) ‡

  • Semiconductor Artificial Semiconductor Artificial SuperlatticeSuperlattice ProductionProductionMolecular beam epitaxy

    GaSi As Be

    Al

    RHEEDpattern

    E-gunScreen

    Substrate

    Accumulate each layer of atoms inside ultra-high-vacuum in a clean environment.

    The artificial superlattice can be obtained by accumulating different types of atomic layers.

    ‡Iye Laboratory, The Institute for Solid State Physics, University of Tokyo.

  • Potential of Artificial Potential of Artificial SuperlatticesSuperlattices

    Electrons get caught

    here.GaAs/AlGaAs

    Gap

    Valence electron band

    Conduction band

  • TwoTwo--dimension Electron System at dimension Electron System at Semiconductor InterfaceSemiconductor Interface

    The electron is confined by potential in the direction perpendicular to the interface while it is freely traveling in the direction parallel to the interface.

    The electron density can be changed by applying electric voltageto the gate electrode.The potential for the electron is artificially induced by using an appropriate form of gate electrode.

    Gate electrodeSource electrode

    Si impurity

    Drain electrode

    Two-dimension electron system

    Two-dimension electron system

  • Examples of Examples of MesoscopicMesoscopic SamplesSamples

    Two-dimension modulat(antidot lattice)

    1mm

    Single-dimension modulation (washboard potential)

    1mm

    Quantum point contactQuantum dot

    Variety of artificial structures are produced by micro-processing of two-dimensional electron system samples.

    Ⓒ Yasuhiro Iye

  • Scanning electron microscopeElectron beam lithography

    Optical microscope

    Dustproof suit

    Operation image in clean room.

    Clean Room OperationClean Room Operation

    Iye Laboratory, The Institute for Solid State Physics, University of Tokyo.

  • Scanning electron microscopeElectron beam lithography

    Emission vent of electron beam

    Sample holder

    Controller

    Electron Beam Lithography SystemElectron Beam Lithography System

    Iye Laboratory, The Institute for Solid State Physics, University of Tokyo. ‡

  • ターゲット

    基板イオンソース

    Ion beam spattering system

    Metal Vapor DepositionMetal Vapor Deposition

    Ion source

    Target

    Foundation base

    Iye Laboratory, The Institute for Solid State Physics, University of Tokyo.

    Ⓒ Yasuhiro Iye ‡

  • ① Cleansing the foundation.

    ② Resist coating ④ Exposure ⑥ Development

    ③ Mask alignment ⑤ After exposure

    Formation of MicroFormation of Micro--patternspatterns

    Ⓒ Yasuhiro Iye ‡

  • Vapor deposition

    Lift-off

    Etching

    Resist removal

    Vapor Deposition and LiftVapor Deposition and Lift--offoff

    Ⓒ Yasuhiro Iye ‡

  • Production of Quantum Structures by Production of Quantum Structures by UltraUltra--micromicro--processingprocessing

    Electron lithography system The quantum dot was produced by micro-processing of the electron lithography.

    The antidot lattice of two-dimension electron system in a semiconductor:Artificial superperiodicstructure. Ⓒ Yasuhiro Iye ‡

    Iye Laboratory, ISSP, University of Tokyo.

  • The example for the micro-structure sample observed by an optical microscope. A single quantum dot is formed both above and below in the structure.

    1.2 mm

    Gold deposited electrodeEtching-treated part

    5μm

    MicroMicro--structure Samplestructure Sample

    Ⓒ Yasuhiro Iye ‡

  • Quantum ConductionQuantum Conduction

  • Conduction Electrons in MetalsConduction Electrons in Metals

    Free electron model

    In metals, there is an electron (conduction electron) that can move around in the entire crystal.

  • Electron is filled from lower energy level

    ⇒Fermi levelFermi surface

    and sphere

    Quantum Mechanics: Particles in a Box Quantum Mechanics: Particles in a Box

    rkr ⋅= ieL31)(ψ

    ),2,1,0(2 L±±== xxx nnLk π

    The permitted wave number of an electron.

    Permissive state of wave number space.

    Lm2

    22 kh=ε

  • Electric ConductionElectric Conduction

    EEv μτ ==me

    E

    EJ

    σ

    τ

    =

    =m

    ne2vJ ne=

    τv

    Ev

    medt

    dm −=

    Electric currentSemi-classical equation of motion

    “Friction” term due to scattering.

    Acceleration due to electric field.

    Electron mobility

    mne τσ

    2

    =

    Drude formula

    Electric field Electric field

  • Velocity of ElectronsVelocity of ElectronsMake s current of one ampere Make s current of one ampere

    into lead wire with cross into lead wire with cross section area 1 mmsection area 1 mm22

    26 A/m10== vJ ne

    mm/s0.06m/s106

    C106.1m105

    19329

    =×≈

    ××−

    −−

    Am10 26=

    =

    neJv

    m/s106F ≈vThe velocity of an electron at the Fermi level is: For ordinary metals:(one hundredth the speed of light)

    329 m10 -n =Conduction electron density of metal:

    Speed of snails??

    kvk k ∂

    ∂==

    εεh

    h 1,2

    22

    m

    If there is no electric field, electrons travel in both directions positive and negative to cancel each other out, and as a result, the net electric current is zero.

    Even a subtle loss of balance can create very large electric current.This is the average speed.

  • TwoTwo--dimension Electron System at dimension Electron System at Semiconductor InterfaceSemiconductor Interface

    Electron density

    HEMT (High Electron Mobility Transistor)

    21613 m10~10 -n =

    Two-dimension electron system

    Two-dimension electron system

    Gate electrodeSource electrode

    Drain electrode

    Si impurity

  • High MobilityHigh Mobility

    Vsm1000 2>μ

    m100 μ>l

    Electron mobility

    Mean free path

    Ballistic conductivityL>l (L: sample size)

    Micro-processing lets us to make samples that are smaller than those shown in the figure. M

    obili

    ty

    Bulk

    Temperature

    Clean bulk

  • MesoscopicMesoscopic CircuitCircuit

    G=GR+GL

    Classical parallel circuitMesoscopic ring

    G≠GR+GL

  • Quantum ResistanceQuantum ResistanceThe quantity of the dimension where the electric resistanbelongs is made of physical constants.

    eh

    Magnetic fluxΦ =voltage×time

    e Electric charge e =electric current×time

    2eh

    Magnetic flux/electric charge= voltage/electric current = electric resistance

    Ω= k813.252eh

    Quantum resistance

    S7.38k813,25

    12 μ=Ω

    =he

    Quantum conductance

  • Conductance QuantizationConductance Quantization

    heN

    RG

    221==Ω

    =k813.25

    12

    he

    Quantum point contact

    2次元電子系量子ポイントコンタクト

    ソース 電極

    ドレイン  電極

    VG

    Drain electrodeSource electrode

    Two-dimensional electron systemQuantum point contact

    Negative bias voltageⒸ Yasuhiro Iye ‡

  • Hall EffectHall Effect

    ⎟⎟⎠

    ⎞⎜⎜⎝

    ⎛⎟⎟⎠

    ⎞⎜⎜⎝

    ⎛=⎟⎟

    ⎞⎜⎜⎝

    ⎛⇒=

    y

    x

    yyyx

    xyxx

    y

    x

    EE

    JJ

    σσσσ

    σ EJ

    B

    B

    E

    vd

    Behavior of electrons in an electrostatic magnetic field.

    ⎟⎟⎠

    ⎞⎜⎜⎝

    ⎛⎟⎟⎠

    ⎞⎜⎜⎝

    ⎛=⎟⎟

    ⎞⎜⎜⎝

    ⎛⇒=

    y

    x

    yyyx

    xyxx

    y

    x

    JJ

    EE

    ρρρρ

    ρ JE

    V

    VH

    I

    W

    ρ

    ρ

    xx

    xyL

    B

    0

    ρxx

    ρxy

    0

    ∝B/neρxy

    ρxx

    B

    neBBxy =)(ρ ρρ =)(Bxx

    ( )k

    vBvEk kkk ∂∂

    =×+=εe

    dtd

    h

    Lorentz force

  • Quantum Hall EffectQuantum Hall Effect

    Ω= k813.252eh

    2

    10

    eh

    Nxy

    xx

    =

    =

    ρ

    ρ

    B00

    ρxx

    ρxyρxy

    ρxx

    h/e2

    h/ e2 2

    h/ e32

    With accuracy of more than eight digits, agrees with h/e2.

    ⇒ International standard of resistance

  • AharonovAharonov--BohmBohm Effect (AB Effect)Effect (AB Effect)

    eh

    de

    de

    de

    de

    ==

    ⋅=⋅=

    ⋅−⋅=Δ

    ∫∫

    ∫∫

    00

    loop

    RL

    2

    )()(

    )()(

    φφφπ

    θ

    SrBrrA

    rrArrA

    hh

    hhPhase change in electron occurs due to the magnetic field (vector potential).

    Electron source

    CoilElectron beam biprism

    Phase difference

    出典確認中

  • AharonovAharonov--BohmBohm Oscillation (AB Oscillation (AB Oscillation)Oscillation)

    The above shows the interference of electron waves that pass through the paths in both sides of the ring.Electric resistance periodically oscillates for the ring penetrating magnetic fluxΦ.

    Wb1014.4 150−×==

    heφ

    eh

    de

    de

    de

    de

    ==

    ⋅=⋅=

    ⋅−⋅=Δ

    ∫∫

    ∫∫

    00

    loop

    RL

    2

    )()(

    )()(

    φφφπ

    θ

    SrBrrA

    rrArrA

    hh

    hh

    Magnetic flux quantum

    h/e oscillation and h/2e oscillation

  • Electron Locality as Quantum Electron Locality as Quantum InterferenceInterference

    h/2e Oscillation

    Φ

    −+ Ψ+Ψ=ΨThe pair is in a relationship of inverse symmetry of time. 0

    22

    2D ln TT

    heP

    mne

    πτσ −=

    Classical conductivity

    Quantum correction

    −+−+−+

    −+

    ΨΨ+ΨΨ+Ψ+Ψ=

    Ψ+Ψ=Ψ**22

    22

    Quantum interference term

    For non-ring structures:

    Conductance fluctuation~e2/h

  • MonoMono--electron Tunnel Effectelectron Tunnel Effect

    Coulomb blockadeElectrostatic potential of island is increased due to tunneling of a single electron.⇒ the following electron cannot go in.

    Micro tunnel junction

    Coulomb island(quantum dot)

  • Quantum Dot (Artificial Atom)Quantum Dot (Artificial Atom)

    Prof. Tarutya, Seigo., School of Science, University of Tokyo ‡

  • Quantum Physics in Quantum Physics in MesoscopicMesoscopic SystemSystemMono-electron tunnel effect Quantum interference effect

    Particle properties Wave properties

    Wave-particle duality of electrons

  • SummarySummaryMesoscopic physics

    Artificially-designed system+state-of-the-art observation

    and measuring methods

    Visible quantum mechanics:wave properties quantum interference effectparticle properties mono-electron tunnel effect

    Magic number e2/h=(25.813kW)-1

    Incorporation of fundamental physics and high-tech

    Review of Lecture 6 (1)Review of Lecture 6 (2)Today’s TopicsOverview of Quantum MechanicsQuantum MechanicsIn Quantum Mechanics, a Particle also Behaves as a WaveQuantum MechanicsUncertainty RelationQuantum-mechanical State and Measured ValueQuantum Mechanical MeasuringCharacteristic Phenomena in Quantum MechanicsQuantum InterferenceLight Wave InterferenceFor Classical ParticlesThe Incident WaveParticles in Quantum MechanicsElectron InterferenceThe Double-slit Experiment of Electron (Dr. Akira Sotomura)Electron InterferenceAharonov-Bohm Effect (AB Effect)How Large Can a Particle Be in Order to Interfere?Same Observation for LightArtificial Materials and Mesoscopic SystemsThe Microscopic UniverseThe Mesoscopic SystemMicro-processing for Semiconductor DevicesMagnetic Recording MediaSilicon Monocrystal ⇒ Wafer ⇒ Super LSIUltra-large Scale Integration Semiconductor (ULSI)The Mesoscopic System Conditions Necessary for Mesoscopic Physics and NanoscienceArtificial SuperlatticeSemiconductor Artificial Superlattice ProductionPotential of Artificial SuperlatticesTwo-dimension Electron System at Semiconductor InterfaceExamples of Mesoscopic SamplesClean Room OperationElectron Beam Lithography SystemMetal Vapor DepositionFormation of Micro-patternsVapor Deposition and Lift-offProduction of Quantum Structures by Ultra-micro-processingMicro-structure SampleQuantum ConductionConduction Electrons in MetalsQuantum Mechanics: Particles in a Box Electric ConductionVelocity of ElectronsTwo-dimension Electron System at Semiconductor InterfaceHigh MobilityMesoscopic CircuitQuantum ResistanceConductance QuantizationHall EffectQuantum Hall EffectAharonov-Bohm Effect (AB Effect)Aharonov-Bohm Oscillation (AB Oscillation) Electron Locality as Quantum InterferenceMono-electron Tunnel EffectQuantum Dot (Artificial Atom)Quantum Physics in Mesoscopic SystemSummary