NONLOCAL TRANSPORT IN GRAPHENE: VALLEY CURRENTS, HYDRODYNAMICS AND ELECTRON VISCOSITY
|
|
- Stuart Gordon
- 6 years ago
- Views:
Transcription
1 NONLOCAL TRANSPORT IN GRAPHENE: VALLEY CURRENTS, HYDRODYNAMICS AND ELECTRON VISCOSITY Leonid Levitov (MIT) Frontiers of Nanoscience ICTP Trieste, August, 2015
2 60 2
3 60 3
4 Boris Blinks the Antiquarian Bookseller 4
5 Valley currents Valleys in Graphene Berry curvature Valleys in MoS2 Valleys in Bulk Si No Berry curvature v xy v xy σ =0 σ 0 5
6 Use Berry curvature to electrically manipulate valleys Valley Hall effect: Transverse charge-neutral currents J v = J K J K ' v J v =σ xy z E 6
7 Collaboration Justin Song Song, Shytov, LL PRL 111, (2013) Song, Samutpraphoot, LL, PNAS (2015) LL & Falkovich arxiv: (2015) Gregory Falkovich 7
8 Topological Bloch bands in graphene superlattices Designer topological materials: stacks of 2D materials which by themselves are not topological, e.g. graphene. Previously, topological bands in graphene were presumed either impossible or impractical Turn graphene into a robust platform with which topological behavior can be realized and explored. 8
9 Goal: develop graphene-based topological materials Quantized transport, Topological bands, Anomalous Hall effects 1 C= Ω (k ) Chern invariant k 2π Ω( k )= k A k, A k =i ψ( k) k ψ(k ) 9
10 Goal: develop graphene-based topological materials Quantized transport, Topological bands, Anomalous Hall effects 1 C= Ω (k ) Chern invariant k 2π Ω( k )= k A k, A k =i ψ( k) k ψ(k ) Pristine graphene: massless Dirac fermions, Berry phase yet no Berry curvature 10
11 Goal: develop graphene-based topological materials Quantized transport, Topological bands, Anomalous Hall effects 1 C= Ω (k ) Chern invariant k 2π Ω( kbenefit )= k Afrom ψ( k) k ψ(k ) k, A k =i graphene's properties Pristinesuperior graphene:electronic massless Dirac fermions, Berry phase yet no Berry curvature 11
12 Massive (gapped) Dirac particles A/B sublattice asymmetry a gap-opening perturbation Berry curvature hot spots above and below the gap T-reversal symmetry: Ω( k )= Ω( k ) Valley Chern invariant (for closed bands) 1 C= Ω (k ) 2π k 12 Ω(k ) 0
13 Massive (gapped) Dirac particles A/B sublattice asymmetry a gap-opening perturbation Berry curvature hot spots above and below the gap T-reversal symmetry: Ω( k )= Ω( k ) Ω(k ) 0 Valley Chern invariant (for closed bands) 1 C= Ω (k ) 2π k D. Xiao, W. Yao, and Q. Niu, PRL 99, (2007) 13
14 The variety of van der Waals heterostructures: G/hBN superlattices Image from: Geim & Grigorieva, Nature 499, 419 (2013) 14
15 Bloch bands in G/hBN superlattices Song, Shytov, LL, PRL 111, (2013) Song, Samutpraphoot, LL, PNAS (2015) Moiré wavelength spacings can be as large as 14nm 100 C-C 15
16 Bloch bands in G/hBN superlattices Song, Shytov, LL, PRL 111, (2013) Song, Samutpraphoot, LL, PNAS (2015) Moiré wavelength spacings can be as large as 14nm 100 C-C 16
17 Bloch bands in G/hBN superlattices Song, Shytov, LL, PRL 111, (2013) Song, Samutpraphoot, LL, PNAS (2015) Focus on one valley, K or K' Bloch Chern minibands w/ Valley Chern invariants Moiré wavelength C-C spacing can as large as 14nm 100 times 17
18 Low-energy Hamiltonian San-Jose et al. (2014), Jung et al (2014), Song, Shytov LL PRL (2013) Wallbank et al PRB (2014), Kindermann PRB (2012) Sachs, et. al. PRB (2011) Constant global gap at DP Spatially varying gap, Bragg scattering Focus on one valley Song, Samutpraphoot, LL PNAS (2015) 18
19 Incommensurate/Moire case 19
20 Commensurate case 20
21 Band topology tunable by crystal axes alignment Topological bands C=1 Trivial bands C=0 21
22 Valley currents Valleys in Graphene Berry curvature v xy σ 0 Valleys in MoS2 Valleys in Bulk Si No Berry curvature v xy σ =0 22
23 Use Berry curvature to electrically manipulate valleys Valley Hall effect: Transverse charge-neutral currents J v = J K J K ' v J v =σ xy z E 23
24 Detecting valley currents 1 3 Valley Current (Neutral) Pump valley imbalance
25 Detecting valley currents 1 3 Valley Current (Neutral) Pump valley imbalance Valley Hall Effect (VHE): 4 2 Reverse Valley Hall Effect (RVHE): 25
26 Detecting valley currents Image credit: wikipedia.com 1 3 Valley Current (Neutral) Pump valley imbalance Valley Hall Effect (VHE): 4 2 Reverse Valley Hall Effect (RVHE): 26
27 (VHE) Gorbachev, Song et al Science 346, 448 (2014) Van der Pauw bound: Berry hot spots 02/19/ Valley Current (RVHE) Nonlocal response in aligned G/hBN
28 (VHE) Gorbachev, Song et al Science 346, 448 (2014) Van der Pauw bound: Berry hot spots 02/19/ Valley Current (RVHE) Nonlocal response in aligned G/hBN
29 (VHE) Gorbachev, Song et al Science 346, 448 (2014) Valley Current Van der Pauw bound: Berry hot spots 02/19/2014 Distance dependence 29 (RVHE) Nonlocal response in aligned G/hBN
30 Checklist 1) Stray ohmic currents too small, peaks in density dependence line up w Berry pockets; mediated by long-range neutral currents 2) Observed at B=0, excludes energy and spin (prev work) 3) Good quantitative agreement w/ topo valley currents for Berry curvature induced by gap opening 4) Seen in aligned G/hBN devices, never in nonaligned devices 5) Scales as cube of xx as expected for valley currents ρxx ρ 02/19/ xx 30
31 Checklist 1) Stray ohmic currents too small, peaks in density dependence line up w Berry pockets; mediated by long-range neutral currents 2) Observed at B=0, excludes energy and spin (prev work) 3) Good quantitative agreement w/ topo valley currents for Berry curvature induced by gap opening 4) Seen in aligned G/hBN devices, never in nonaligned devices 5) Scales as cube of xx as expected for valley currents ρxx ρ 02/19/ xx 31
32 Checklist 1) Stray ohmic currents too small, peaks in density dependence line up w Berry pockets; mediated by long-range neutral currents 2) Observed at B=0, excludes energy and spin (prev work) 3) Good quantitative agreement w/ topo valley currents for Berry curvature induced by gap opening 4) Seen in aligned G/hBN devices, never in nonaligned devices 5) Scales as cube of xx as expected for valley currents ρxx ρ 02/19/ xx 32
33 Valley transistor: proof of concept 1) Full separation of valley and charge current 2) ~140 mv/decade 3) Gate-tunable valley current Modulation > 100 fold
34 Valley transistor: proof of concept 1) Full separation of valley and charge current 2) ~140 mv/decade 3) Gate-tunable valley current Modulation > 100 fold Spin Transistor? Koo, et. al., Science (2009), see also Gorbachev, Song, et. al., Science (2014) Wunderlich, et. al., Science (2010) Original Proposal: Datta, Das, APL (1990)
35 Summary Valley currents: charge-neutral, can mediate longrange electrical response Excited and detected using the Valley Hall effect Graphene superlattices as a platform for designer topological bands Bloch minibands w/ nontrivial Valley Chern numbers Tunable by twist angle, topological transitions Topological domains, protected edge modes 35
36 Summary Valley currents: charge-neutral, can mediate longrange electrical response Excited and detected using the Valley Hall effect Graphene superlattices as a platform for designer topological bands Bloch minibands w/ nontrivial Valley Chern numbers Tunable by twist angle, topological transitions Topological domains, protected edge modes 36
37 Summary Valley currents: charge-neutral, can mediate longrange electrical response Excited and detected using the Valley Hall effect Graphene superlattices as a platform for designer topological bands Bloch minibands w/ nontrivial Valley Chern numbers Tunable by twist angle, topological transitions Topological domains, protected edge modes 37
38 Electron Viscosity and Nonlocal Response Is hydrodynamics ever relevant? 38
39 Is hydrodynamics ever relevant? In one-comp fluid or gas a hydrodynamic approach works b/c one has local conservation of energy and momentum All transport properties governed by just 3 quantities: the shear viscosity ( ), the second viscosity ( ), and the thermal conductivity ( ) 39
40 Is hydrodynamics ever relevant in metals? In one-comp fluid or gas a hydrodynamic approach works b/c one has local conservation of energy and momentum All transport properties governed by just 3 quantities: the shear viscosity ( ), the second viscosity ( ), and the thermal conductivity ( ) Electron fluid in a solid can exchange energy and momentum with the lattice. Hydrodynamics not relevant? Not so fast... 40
41 Is hydrodynamics ever relevant in metals? In one-comp fluid or gas a hydrodynamic approach works b/c one has local conservation of energy and momentum All transport properties governed by just 3 quantities: the shear viscosity ( ), the second viscosity ( ), and the thermal conductivity ( ) Electron fluid in a solid can exchange energy and momentum with the lattice. Hydrodynamics not relevant? Not so fast... High-mobility 2DEGs: collisions of the fluid with "large" objects e.g. some slowly varying background impurity potential lee << (disorder correlation length) 41
42 Is hydrodynamics ever relevant in metals? In one-comp fluid or gas a hydrodynamic approach works b/c one has local conservation of energy and momentum All transport properties governed by just 3 quantities: the shear viscosity ( ), the second viscosity ( ), and the thermal conductivity ( ) Electron fluid in a solid can exchange energy and momentum with the lattice. Hydrodynamics not relevant? Not so fast... High-mobility 2DEGs: collisions of the fluid with "large" objects e.g. some slowly varying background impurity potential lee << 42
43 Is hydrodynamics ever relevant in metals? In one-comp fluid or gas a hydrodynamic approach works b/c one has local conservation of energy and momentum All transport properties governed by just 3 quantities: the shear viscosity ( ), the second viscosity ( ), and the thermal conductivity ( ) Electron fluid in a solid can exchange energy and momentum with the lattice. Hydrodynamics not relevant? Not so fast... High-mobility 2DEGs: collisions of the fluid with "large" objects e.g. some slowly varying background impurity potential lee << 43
44 Collisions of ballistic carriers Temperature-dependent scattering time ee~(ef/t)^2 Sample width w << lee (low T) Knudsen-Fuchs regime w w >> lee (higher T) Poiseuille-Gurzhi regime Control value ee by current 44
45 Collisions of ballistic carriers Temperature-dependent scattering time ee~(ef/t)^2 Sample width w << lee (low T) Knudsen-Fuchs regime w w >> lee (higher T) Poiseuille-Gurzhi regime Control value ee by current Gurzhi effect: p-relaxation slows down due to diffusion R=dV/dI vs. I first grows then decreases 45
46 Collisions of ballistic carriers Temperature-dependent scattering time ee~(ef/t)^2 Sample width w << lee (low T) Knudsen-Fuchs regime w w >> lee (higher T) Poiseuille-Gurzhi regime Control value ee by current Gurzhi effect: p-relaxation slows down due to diffusion R=dV/dI vs. I first grows then decreases Tested in ballistic wires de Jong & Molenkamp
47 Critical electron fluid in graphene Interactions enhanced in 2D, strong near DP Vanishing DOS but long-range interactions, strong coupling Fast p-conserving collisions, high shear viscosity Low viscosity-to-entropy ratio /s (near-perfect fluid) Comparable to universal low bound (AdS CFT, black holes 47
48 Critical electron fluid in graphene Interactions enhanced in 2D, strong near DP Vanishing DOS but long-range interactions, strong coupling Fast p-conserving collisions, shear viscosity Low viscosity-to-entropy ratio /s (near-perfect fluid) Comparable to universal low bound (AdS CFT, black holes 48
49 Critical electron fluid in graphene Interactions enhanced in 2D, strong near DP Vanishing DOS but long-range interactions, strong coupling Fast p-conserving collisions, shear viscosity Low viscosity-to-entropy ratio /s (near-perfect fluid) Comparable to universal low bound (AdS CFT, black holes 49
50 Critical electron fluid in graphene Interactions enhanced in 2D, strong near DP Vanishing DOS but long-range interactions, strong coupling Fast p-conserving collisions, shear viscosity Low viscosity-to-entropy ratio /s (near-perfect fluid) Comparable to universal low bound (AdS CFT, black holes) 50
51 Measure viscosity? Scaling with system dimensions: R~L/W (Ohmic regime) vs. R~L/W^2 (Poiseuille-Gurzhi regime) Mueller, Shmalian, Fritz 51
52 Measure viscosity? Scaling with system dimensions: R~L/W (Ohmic regime) vs. R~L/W^2 (Poiseuille-Gurzhi regime) Corbino geometry with a time-varying flux (Tomadin, Vignale, Polini) Mueller, Shmalian, Fritz 52
53 Measure viscosity? Scaling with system dimensions: R~L/W (Ohmic regime) vs. R~L/W^2 (Poiseuille-Gurzhi regime) Corbino geometry with a time-varying flux (Tomadin, Vignale, Polini) Mueller, Shmalian, Fritz Challenge: do it w/ 1) one device; 2) linear response (no heating); 3) a DC measurement (no time dependence) 53
54 Negative nonlocal resistance Vortices launched by shear flow Reverse E field buildup due to backflow
55 Negative nonlocal resistance Vortices launched by shear flow Reverse E field buildup due to backflow Minus sign: analogous to Coulomb drag 55
56 Viscous vs. ohmic flow: a sign change 56
57 Minimal model Continuity equation and momentum transport equation 1 t n+ (n v )=0, t pi + i σ ij = τ pi 1 σ ij = η( i v j + j v i k v k δij )+( ζ k v k + P) δij 2 First and second viscosity (shear and dilation) P=n(μ +e Φ) Boundary conditions: continuity; realistic (partial slippage); idealized (no-slip) 1: v n =0 2 : v t =α E t 2 ' : v t=0 57
58 Solving for incompressible flow Introduce a flow function: 1 v = ψ ( τ =0) ν v = P ( ) ψ=0 ikx ky ky ψ( x, y)= k e ((a+by ) e +(a ' +b ' y ) e ) 58
59 Solving for incompressible flow Introduce a flow function: 1 v = ψ ( τ =0) ν v = P ( ) ψ=0 ikx ky ky ψ( x, y)= k e ((a+by ) e +(a ' +b ' y ) e ) V ( L)= ( k e ikl ν k tanh( kw/ 2) sinh(kw) kw+ sinh(kw)+α k 59 2 ) I
60 Solving for incompressible flow Introduce a flow function: 1 v = ψ ( τ =0) ν v = P ( ) ψ=0 ikx ky ky ψ( x, y)= k e ((a+by ) e +(a ' +b ' y ) e ) V ( L)= ( k e ikl ν k tanh( kw/ 2) sinh(kw) kw+ sinh(kw)+α k 2 ) I Positive in Fourier space (2 peaks), negative in real space At very large L positive again due to residual ohmic effects Can use to measure the ratio 60
61 Solving for incompressible flow Introduce a flow function: 1 v = ψ ( τ =0) ν v = P ( ) ψ=0 ikx ky ky ψ( x, y)= k e ((a+by ) e +(a ' +b ' y ) e ) V ( L)= ( k e ikl ν k tanh( kw/ 2) sinh(kw) kw+ sinh( kw )+α k 2 ) I Positive in Fourier space (2 peaks), negative in real space At very large L positive again due to residual ohmic effects Can use to directly measure the ratio 61
62 Summary / Future Vortices launched by shear flow Backflow leading to negative nonlocal voltage Sign change as a function of position, if observed, allows to directly measure the viscosity-to-resistivity ratio Experiments in high-mobility 2DEGs (GaAs, graphene) Caveats? Beware of other neutral modes. Negative thermoelectric effect due to energy flow. Control by lattice cooling Next challenge: measure second viscosity 63
63 Summary / Future Vortices launched by shear flow Backflow leading to negative nonlocal voltage Sign change as a function of position, if observed, allows to directly measure the viscosity-to-resistivity ratio Experiments in high-mobility 2DEGs (GaAs, graphene) Caveats? Beware of other neutral modes. Negative thermoelectric effect due to energy flow. Control by lattice cooling? Next challenge: measure second viscosity ( string theory : =0 due to conformal symmetry) 64
64 Summary / Future Vortices launched by shear flow Backflow leading to negative nonlocal voltage Sign change as a function of position, if observed, allows to directly measure the viscosity-to-resistivity ratio Experiments in high-mobility 2DEGs (GaAs, graphene) Caveats? Beware of other neutral modes. Negative thermoelectric effect due to energy flow. Control by lattice cooling? Next challenge: measure second viscosity ( string theory : =0 due to conformal symmetry) 65
TOPOLOGICAL BANDS IN GRAPHENE SUPERLATTICES
TOPOLOGICAL BANDS IN GRAPHENE SUPERLATTICES 1) Berry curvature in superlattice bands 2) Energy scales for Moire superlattices 3) Spin-Hall effect in graphene Leonid Levitov (MIT) @ ISSP U Tokyo MIT Manchester
More informationfluid mechanics? Why solid people need Falkovich WIS April 14, 2017 UVA
Why solid people need fluid mechanics? Falkovich WIS 1. L Levitov & G Falkovich, Electron viscosity, current vortices and negative nonlocal resistance in graphene. Nature Physics 12 : 672-676 (2016) 2.
More informationValley Hall effect in electrically spatial inversion symmetry broken bilayer graphene
NPSMP2015 Symposium 2015/6/11 Valley Hall effect in electrically spatial inversion symmetry broken bilayer graphene Yuya Shimazaki 1, Michihisa Yamamoto 1, 2, Ivan V. Borzenets 1, Kenji Watanabe 3, Takashi
More informationSpin Superfluidity and Graphene in a Strong Magnetic Field
Spin Superfluidity and Graphene in a Strong Magnetic Field by B. I. Halperin Nano-QT 2016 Kyiv October 11, 2016 Based on work with So Takei (CUNY), Yaroslav Tserkovnyak (UCLA), and Amir Yacoby (Harvard)
More informationViscous electron fluids: Superballistic conduction; Odd-parity hydrodynamics
Viscous electron fluids: Superballistic conduction; Odd-parity hydrodynamics Leonid Levitov (MIT) Frontiers in Many-Body Physics Memorial for Lev Petrovich Gor kov Tallahassee, 01/13/018 Hydrodynamics:
More informationRelativistic magnetotransport in graphene
Relativistic magnetotransport in graphene Markus Müller in collaboration with Lars Fritz (Harvard) Subir Sachdev (Harvard) Jörg Schmalian (Iowa) Landau Memorial Conference June 6, 008 Outline Relativistic
More informationTopological insulator (TI)
Topological insulator (TI) Haldane model: QHE without Landau level Quantized spin Hall effect: 2D topological insulators: Kane-Mele model for graphene HgTe quantum well InAs/GaSb quantum well 3D topological
More informationQuantum Hall Effect in Graphene p-n Junctions
Quantum Hall Effect in Graphene p-n Junctions Dima Abanin (MIT) Collaboration: Leonid Levitov, Patrick Lee, Harvard and Columbia groups UIUC January 14, 2008 Electron transport in graphene monolayer New
More informationTransient grating measurements of spin diffusion. Joe Orenstein UC Berkeley and Lawrence Berkeley National Lab
Transient grating measurements of spin diffusion Joe Orenstein UC Berkeley and Lawrence Berkeley National Lab LBNL, UC Berkeley and UCSB collaboration Chris Weber, Nuh Gedik, Joel Moore, JO UC Berkeley
More informationChapter 3 Properties of Nanostructures
Chapter 3 Properties of Nanostructures In Chapter 2, the reduction of the extent of a solid in one or more dimensions was shown to lead to a dramatic alteration of the overall behavior of the solids. Generally,
More informationTutorial: Berry phase and Berry curvature in solids
Tutorial: Berry phase and Berry curvature in solids Justin Song Division of Physics, Nanyang Technological University (Singapore) & Institute of High Performance Computing (Singapore) Funding: (Singapore)
More informationAditi Mitra New York University
Entanglement dynamics following quantum quenches: pplications to d Floquet chern Insulator and 3d critical system diti Mitra New York University Supported by DOE-BES and NSF- DMR Daniel Yates, PhD student
More informationCoulomb Drag in Graphene
Graphene 2017 Coulomb Drag in Graphene -Toward Exciton Condensation Philip Kim Department of Physics, Harvard University Coulomb Drag Drag Resistance: R D = V 2 / I 1 Onsager Reciprocity V 2 (B)/ I 1 =
More informationPersistent spin helix in spin-orbit coupled system. Joe Orenstein UC Berkeley and Lawrence Berkeley National Lab
Persistent spin helix in spin-orbit coupled system Joe Orenstein UC Berkeley and Lawrence Berkeley National Lab Persistent spin helix in spin-orbit coupled system Jake Koralek, Chris Weber, Joe Orenstein
More informationCorrelated 2D Electron Aspects of the Quantum Hall Effect
Correlated 2D Electron Aspects of the Quantum Hall Effect Magnetic field spectrum of the correlated 2D electron system: Electron interactions lead to a range of manifestations 10? = 4? = 2 Resistance (arb.
More informationField Theory Description of Topological States of Matter. Andrea Cappelli INFN, Florence (w. E. Randellini, J. Sisti)
Field Theory Description of Topological States of Matter Andrea Cappelli INFN, Florence (w. E. Randellini, J. Sisti) Topological States of Matter System with bulk gap but non-trivial at energies below
More informationTopological Defects inside a Topological Band Insulator
Topological Defects inside a Topological Band Insulator Ashvin Vishwanath UC Berkeley Refs: Ran, Zhang A.V., Nature Physics 5, 289 (2009). Hosur, Ryu, AV arxiv: 0908.2691 Part 1: Outline A toy model of
More informationSUPPLEMENTARY INFORMATION
doi:1.138/nature12186 S1. WANNIER DIAGRAM B 1 1 a φ/φ O 1/2 1/3 1/4 1/5 1 E φ/φ O n/n O 1 FIG. S1: Left is a cartoon image of an electron subjected to both a magnetic field, and a square periodic lattice.
More informationFluid dynamics of electrons in graphene. Andrew Lucas
Fluid dynamics of electrons in graphene Andrew Lucas Stanford Physics Condensed Matter Seminar, Princeton October 17, 2016 Collaborators 2 Subir Sachdev Harvard Physics & Perimeter Institute Philip Kim
More informationBerry Phase Effects on Electronic Properties
Berry Phase Effects on Electronic Properties Qian Niu University of Texas at Austin Collaborators: D. Xiao, W. Yao, C.P. Chuu, D. Culcer, J.R.Shi, Y.G. Yao, G. Sundaram, M.C. Chang, T. Jungwirth, A.H.MacDonald,
More informationGraphene: massless electrons in flatland.
Graphene: massless electrons in flatland. Enrico Rossi Work supported by: University of Chile. Oct. 24th 2008 Collaorators CMTC, University of Maryland Sankar Das Sarma Shaffique Adam Euyuong Hwang Roman
More informationDesign and realization of exotic quantum phases in atomic gases
Design and realization of exotic quantum phases in atomic gases H.P. Büchler and P. Zoller Theoretische Physik, Universität Innsbruck, Austria Institut für Quantenoptik und Quanteninformation der Österreichischen
More informationTopological Insulators
Topological Insulators Aira Furusai (Condensed Matter Theory Lab.) = topological insulators (3d and 2d) Outline Introduction: band theory Example of topological insulators: integer quantum Hall effect
More informationBerry Phase Effects on Charge and Spin Transport
Berry Phase Effects on Charge and Spin Transport Qian Niu 牛谦 University of Texas at Austin 北京大学 Collaborators: Shengyuan Yang, C.P. Chuu, D. Xiao, W. Yao, D. Culcer, J.R.Shi, Y.G. Yao, G. Sundaram, M.C.
More informationThe Superfluid-Insulator transition
The Superfluid-Insulator transition Boson Hubbard model M.P. A. Fisher, P.B. Weichmann, G. Grinstein, and D.S. Fisher, Phys. Rev. B 40, 546 (1989). Superfluid-insulator transition Ultracold 87 Rb atoms
More informationBloch, Landau, and Dirac: Hofstadter s Butterfly in Graphene. Philip Kim. Physics Department, Columbia University
Bloch, Landau, and Dirac: Hofstadter s Butterfly in Graphene Philip Kim Physics Department, Columbia University Acknowledgment Prof. Cory Dean (now at CUNY) Lei Wang Patrick Maher Fereshte Ghahari Carlos
More informationPreface Introduction to the electron liquid
Table of Preface page xvii 1 Introduction to the electron liquid 1 1.1 A tale of many electrons 1 1.2 Where the electrons roam: physical realizations of the electron liquid 5 1.2.1 Three dimensions 5 1.2.2
More informationScaling Anomaly and Atomic Collapse Collective Energy Propagation at Charge Neutrality
Scaling Anomaly and Atomic Collapse Collective Energy Propagation at Charge Neutrality Leonid Levitov (MIT) Electron Interactions in Graphene FTPI, University of Minnesota 05/04/2013 Scaling symmetry:
More informationExperimental Reconstruction of the Berry Curvature in a Floquet Bloch Band
Experimental Reconstruction of the Berry Curvature in a Floquet Bloch Band Christof Weitenberg with: Nick Fläschner, Benno Rem, Matthias Tarnowski, Dominik Vogel, Dirk-Sören Lühmann, Klaus Sengstock Rice
More informationSpins and spin-orbit coupling in semiconductors, metals, and nanostructures
B. Halperin Spin lecture 1 Spins and spin-orbit coupling in semiconductors, metals, and nanostructures Behavior of non-equilibrium spin populations. Spin relaxation and spin transport. How does one produce
More informationQuantum Confinement in Graphene
Quantum Confinement in Graphene from quasi-localization to chaotic billards MMM dominikus kölbl 13.10.08 1 / 27 Outline some facts about graphene quasibound states in graphene numerical calculation of
More informationMinimal Update of Solid State Physics
Minimal Update of Solid State Physics It is expected that participants are acquainted with basics of solid state physics. Therefore here we will refresh only those aspects, which are absolutely necessary
More informationDirac fermions in condensed matters
Dirac fermions in condensed matters Bohm Jung Yang Department of Physics and Astronomy, Seoul National University Outline 1. Dirac fermions in relativistic wave equations 2. How do Dirac fermions appear
More information5 Topological insulator with time-reversal symmetry
Phys62.nb 63 5 Topological insulator with time-reversal symmetry It is impossible to have quantum Hall effect without breaking the time-reversal symmetry. xy xy. If we want xy to be invariant under, xy
More informationGeneral relativity and the cuprates
General relativity and the cuprates Gary T. Horowitz and Jorge E. Santos Department of Physics, University of California, Santa Barbara, CA 93106, U.S.A. E-mail: gary@physics.ucsb.edu, jss55@physics.ucsb.edu
More informationQuantum disordering magnetic order in insulators, metals, and superconductors
Quantum disordering magnetic order in insulators, metals, and superconductors Perimeter Institute, Waterloo, May 29, 2010 Talk online: sachdev.physics.harvard.edu HARVARD Cenke Xu, Harvard arxiv:1004.5431
More informationBerry-phase Approach to Electric Polarization and Charge Fractionalization. Dennis P. Clougherty Department of Physics University of Vermont
Berry-phase Approach to Electric Polarization and Charge Fractionalization Dennis P. Clougherty Department of Physics University of Vermont Outline Quick Review Berry phase in quantum systems adiabatic
More informationExploring Topological Phases With Quantum Walks
Exploring Topological Phases With Quantum Walks Tk Takuya Kitagawa, Erez Berg, Mark Rudner Eugene Demler Harvard University References: PRA 82:33429 and PRB 82:235114 (2010) Collaboration with A. White
More informationTopological Insulators in 3D and Bosonization
Topological Insulators in 3D and Bosonization Andrea Cappelli, INFN Florence (w. E. Randellini, J. Sisti) Outline Topological states of matter: bulk and edge Fermions and bosons on the (1+1)-dimensional
More informationLifshitz Hydrodynamics
Lifshitz Hydrodynamics Yaron Oz (Tel-Aviv University) With Carlos Hoyos and Bom Soo Kim, arxiv:1304.7481 Outline Introduction and Summary Lifshitz Hydrodynamics Strange Metals Open Problems Strange Metals
More informationQuantum Quenches in Chern Insulators
Quantum Quenches in Chern Insulators Nigel Cooper Cavendish Laboratory, University of Cambridge CUA Seminar M.I.T., November 10th, 2015 Marcello Caio & Joe Bhaseen (KCL), Stefan Baur (Cambridge) M.D. Caio,
More informationCommensuration and Incommensuration in the van der Waals Heterojunctions. Philip Kim Physics Department Harvard University
Commensuration and Incommensuration in the van der Waals Heterojunctions Philip Kim Physics Department Harvard University Rise of 2D van der Waals Systems graphene Metal-Chalcogenide Bi 2 Sr 2 CaCu 2 O
More informationBerry s phase in Hall Effects and Topological Insulators
Lecture 6 Berry s phase in Hall Effects and Topological Insulators Given the analogs between Berry s phase and vector potentials, it is not surprising that Berry s phase can be important in the Hall effect.
More informationImpact of disorder and topology in two dimensional systems at low carrier densities
Impact of disorder and topology in two dimensional systems at low carrier densities A Thesis Submitted For the Degree of Doctor of Philosophy in the Faculty of Science by Mohammed Ali Aamir Department
More informationPhysics of Semiconductors
Physics of Semiconductors 13 th 2016.7.11 Shingo Katsumoto Department of Physics and Institute for Solid State Physics University of Tokyo Outline today Laughlin s justification Spintronics Two current
More informationEffective Field Theories of Topological Insulators
Effective Field Theories of Topological Insulators Eduardo Fradkin University of Illinois at Urbana-Champaign Workshop on Field Theoretic Computer Simulations for Particle Physics and Condensed Matter
More informationNanoscale Energy Transport and Conversion A Parallel Treatment of Electrons, Molecules, Phonons, and Photons
Nanoscale Energy Transport and Conversion A Parallel Treatment of Electrons, Molecules, Phonons, and Photons Gang Chen Massachusetts Institute of Technology OXFORD UNIVERSITY PRESS 2005 Contents Foreword,
More informationElectronic properties of graphene. Jean-Noël Fuchs Laboratoire de Physique des Solides Université Paris-Sud (Orsay)
Electronic properties of graphene Jean-Noël Fuchs Laboratoire de Physique des Solides Université Paris-Sud (Orsay) Cargèse, September 2012 3 one-hour lectures in 2 x 1,5h on electronic properties of graphene
More informationMagneto-plasmonic effects in epitaxial graphene
Magneto-plasmonic effects in epitaxial graphene Alexey Kuzmenko University of Geneva Graphene Nanophotonics Benasque, 4 March 13 Collaborators I. Crassee, N. Ubrig, I. Nedoliuk, J. Levallois, D. van der
More informationThe Valley Hall Effect in MoS2 Transistors
Journal Club 2017/6/28 The Valley Hall Effect in MoS2 Transistors Kagimura arxiv:1403.5039 [cond-mat.mes-hall] Kin Fai Mak 1,2, Kathryn L. McGill 2, Jiwoong Park 1,3, and Paul L. McEuen Electronics Spintronics
More informationTopological Insulators and Superconductors
Topological Insulators and Superconductors Lecture #1: Topology and Band Theory Lecture #: Topological Insulators in and 3 dimensions Lecture #3: Topological Superconductors, Majorana Fermions an Topological
More information3D Weyl metallic states realized in the Bi 1-x Sb x alloy and BiTeI. Heon-Jung Kim Department of Physics, Daegu University, Korea
3D Weyl metallic states realized in the Bi 1-x Sb x alloy and BiTeI Heon-Jung Kim Department of Physics, Daegu University, Korea Content 3D Dirac metals Search for 3D generalization of graphene Bi 1-x
More informationBuilding a theory of transport for strange metals. Andrew Lucas
Building a theory of transport for strange metals Andrew Lucas Stanford Physics 290K Seminar, UC Berkeley February 13, 2017 Collaborators 2 Julia Steinberg Harvard Physics Subir Sachdev Harvard Physics
More informationPOEM: Physics of Emergent Materials
POEM: Physics of Emergent Materials Nandini Trivedi L1: Spin Orbit Coupling L2: Topology and Topological Insulators Tutorials: May 24, 25 (2017) Scope of Lectures and Anchor Points: 1.Spin-Orbit Interaction
More informationTopological insulator part I: Phenomena
Phys60.nb 5 Topological insulator part I: Phenomena (Part II and Part III discusses how to understand a topological insluator based band-structure theory and gauge theory) (Part IV discusses more complicated
More informationEmergent topological phenomena in antiferromagnets with noncoplanar spins
Emergent topological phenomena in antiferromagnets with noncoplanar spins - Surface quantum Hall effect - Dimensional crossover Bohm-Jung Yang (RIKEN, Center for Emergent Matter Science (CEMS), Japan)
More informationFloquet Topological Insulators and Majorana Modes
Floquet Topological Insulators and Majorana Modes Manisha Thakurathi Journal Club Centre for High Energy Physics IISc Bangalore January 17, 2013 References Floquet Topological Insulators by J. Cayssol
More informationCarbon based Nanoscale Electronics
Carbon based Nanoscale Electronics 09 02 200802 2008 ME class Outline driving force for the carbon nanomaterial electronic properties of fullerene exploration of electronic carbon nanotube gold rush of
More informationTopology and Fractionalization in 2D Electron Systems
Lectures on Mesoscopic Physics and Quantum Transport, June 1, 018 Topology and Fractionalization in D Electron Systems Xin Wan Zhejiang University xinwan@zju.edu.cn Outline Two-dimensional Electron Systems
More informationTopological Defects in the Topological Insulator
Topological Defects in the Topological Insulator Ashvin Vishwanath UC Berkeley arxiv:0810.5121 YING RAN Frank YI ZHANG Quantum Hall States Exotic Band Topology Topological band Insulators (quantum spin
More informationTwo Dimensional Chern Insulators, the Qi-Wu-Zhang and Haldane Models
Two Dimensional Chern Insulators, the Qi-Wu-Zhang and Haldane Models Matthew Brooks, Introduction to Topological Insulators Seminar, Universität Konstanz Contents QWZ Model of Chern Insulators Haldane
More informationSpin Transport in III-V Semiconductor Structures
Spin Transport in III-V Semiconductor Structures Ki Wook Kim, A. A. Kiselev, and P. H. Song Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695-7911 We
More informationInteger quantum Hall effect for bosons: A physical realization
Integer quantum Hall effect for bosons: A physical realization T. Senthil (MIT) and Michael Levin (UMCP). (arxiv:1206.1604) Thanks: Xie Chen, Zhengchen Liu, Zhengcheng Gu, Xiao-gang Wen, and Ashvin Vishwanath.
More informationPhysics of Low-Dimensional Semiconductor Structures
Physics of Low-Dimensional Semiconductor Structures Edited by Paul Butcher University of Warwick Coventry, England Norman H. March University of Oxford Oxford, England and Mario P. Tosi Scuola Normale
More informationSIGNATURES OF SPIN-ORBIT DRIVEN ELECTRONIC TRANSPORT IN TRANSITION- METAL-OXIDE INTERFACES
SIGNATURES OF SPIN-ORBIT DRIVEN ELECTRONIC TRANSPORT IN TRANSITION- METAL-OXIDE INTERFACES Nicandro Bovenzi Bad Honnef, 19-22 September 2016 LAO/STO heterostructure: conducting interface between two insulators
More informationFerromagnetism and Anomalous Hall Effect in Graphene
Ferromagnetism and Anomalous Hall Effect in Graphene Jing Shi Department of Physics & Astronomy, University of California, Riverside Graphene/YIG Introduction Outline Proximity induced ferromagnetism Quantized
More informationNanoscience, MCC026 2nd quarter, fall Quantum Transport, Lecture 1/2. Tomas Löfwander Applied Quantum Physics Lab
Nanoscience, MCC026 2nd quarter, fall 2012 Quantum Transport, Lecture 1/2 Tomas Löfwander Applied Quantum Physics Lab Quantum Transport Nanoscience: Quantum transport: control and making of useful things
More informationTopological Properties of Quantum States of Condensed Matter: some recent surprises.
Topological Properties of Quantum States of Condensed Matter: some recent surprises. F. D. M. Haldane Princeton University and Instituut Lorentz 1. Berry phases, zero-field Hall effect, and one-way light
More informationarxiv: v1 [cond-mat.mes-hall] 24 Oct 2017
Alternating currents and shear waves in viscous electronics M. Semenyakin 1,,3 and G. Falkovich 4,5 1 Center for Advanced Studies, Skolkovo Institute of Science and Technology, Moscow, Russia Taras Shevchenko
More informationBasic Semiconductor Physics
Chihiro Hamaguchi Basic Semiconductor Physics With 177 Figures and 25 Tables Springer 1. Energy Band Structures of Semiconductors 1 1.1 Free-Electron Model 1 1.2 Bloch Theorem 3 1.3 Nearly Free Electron
More informationTopological insulator part II: Berry Phase and Topological index
Phys60.nb 11 3 Topological insulator part II: Berry Phase and Topological index 3.1. Last chapter Topological insulator: an insulator in the bulk and a metal near the boundary (surface or edge) Quantum
More informationJ10M.1 - Rod on a Rail (M93M.2)
Part I - Mechanics J10M.1 - Rod on a Rail (M93M.2) J10M.1 - Rod on a Rail (M93M.2) s α l θ g z x A uniform rod of length l and mass m moves in the x-z plane. One end of the rod is suspended from a straight
More informationThe Quantum Spin Hall Effect
The Quantum Spin Hall Effect Shou-Cheng Zhang Stanford University with Andrei Bernevig, Taylor Hughes Science, 314,1757 2006 Molenamp et al, Science, 318, 766 2007 XL Qi, T. Hughes, SCZ preprint The quantum
More informationReciprocal Space Magnetic Field: Physical Implications
Reciprocal Space Magnetic Field: Physical Implications Junren Shi ddd Institute of Physics Chinese Academy of Sciences November 30, 2005 Outline Introduction Implications Conclusion 1 Introduction 2 Physical
More informationTopological Physics in Band Insulators II
Topological Physics in Band Insulators II Gene Mele University of Pennsylvania Topological Insulators in Two and Three Dimensions The canonical list of electric forms of matter is actually incomplete Conductor
More informationBasics of topological insulator
011/11/18 @ NTU Basics of topological insulator Ming-Che Chang Dept of Physics, NTNU A brief history of insulators Band insulator (Wilson, Bloch) Mott insulator Anderson insulator Quantum Hall insulator
More informationThe Quantum Hall Effects
The Quantum Hall Effects Integer and Fractional Michael Adler July 1, 2010 1 / 20 Outline 1 Introduction Experiment Prerequisites 2 Integer Quantum Hall Effect Quantization of Conductance Edge States 3
More informationQuantum Transport in Disordered Topological Insulators
Quantum Transport in Disordered Topological Insulators Vincent Sacksteder IV, Royal Holloway, University of London Quansheng Wu, ETH Zurich Liang Du, University of Texas Austin Tomi Ohtsuki and Koji Kobayashi,
More informationGraphite, graphene and relativistic electrons
Graphite, graphene and relativistic electrons Introduction Physics of E. graphene Y. Andrei Experiments Rutgers University Transport electric field effect Quantum Hall Effect chiral fermions STM Dirac
More informationHydrodynamic transport in the Dirac fluid in graphene. Andrew Lucas
Hydrodynamic transport in the Dirac fluid in graphene Andrew Lucas Harvard Physics Condensed Matter Seminar, MIT November 4, 2015 Collaborators 2 Subir Sachdev Harvard Physics & Perimeter Institute Philip
More informationA BIT OF MATERIALS SCIENCE THEN PHYSICS
GRAPHENE AND OTHER D ATOMIC CRYSTALS Andre Geim with many thanks to K. Novoselov, S. Morozov, D. Jiang, F. Schedin, I. Grigorieva, J. Meyer, M. Katsnelson A BIT OF MATERIALS SCIENCE THEN PHYSICS CARBON
More informationTopological insulators. Pavel Buividovich (Regensburg)
Topological insulators Pavel Buividovich (Regensburg) Hall effect Classical treatment Dissipative motion for point-like particles (Drude theory) Steady motion Classical Hall effect Cyclotron frequency
More informationNanostructured Carbon Allotropes as Weyl-Like Semimetals
Nanostructured Carbon Allotropes as Weyl-Like Semimetals Shengbai Zhang Department of Physics, Applied Physics & Astronomy Rensselaer Polytechnic Institute symmetry In quantum mechanics, symmetry can be
More informationMetals: the Drude and Sommerfeld models p. 1 Introduction p. 1 What do we know about metals? p. 1 The Drude model p. 2 Assumptions p.
Metals: the Drude and Sommerfeld models p. 1 Introduction p. 1 What do we know about metals? p. 1 The Drude model p. 2 Assumptions p. 2 The relaxation-time approximation p. 3 The failure of the Drude model
More informationKAVLI v F. Curved graphene revisited. María A. H. Vozmediano. Instituto de Ciencia de Materiales de Madrid CSIC
KAVLI 2012 v F Curved graphene revisited María A. H. Vozmediano Instituto de Ciencia de Materiales de Madrid CSIC Collaborators ICMM(Graphene group) http://www.icmm.csic.es/gtg/ A. Cano E. V. Castro J.
More informationQuantum Hall Effect in Vanishing Magnetic Fields
Quantum Hall Effect in Vanishing Magnetic Fields Wei Pan Sandia National Labs Sandia is a multi-mission laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department
More informationTopological Kondo Insulator SmB 6. Tetsuya Takimoto
Topological Kondo Insulator SmB 6 J. Phys. Soc. Jpn. 80 123720, (2011). Tetsuya Takimoto Department of Physics, Hanyang University Collaborator: Ki-Hoon Lee (POSTECH) Content 1. Introduction of SmB 6 in-gap
More informationSpin-orbit effects in graphene and graphene-like materials. Józef Barnaś
Spin-orbit effects in graphene and graphene-like materials Józef Barnaś Faculty of Physics, Adam Mickiewicz University, Poznań & Institute of Molecular Physics PAN, Poznań In collaboration with: A. Dyrdał,
More informationThe uses of Instantons for classifying Topological Phases
The uses of Instantons for classifying Topological Phases - anomaly-free and chiral fermions Juven Wang, Xiao-Gang Wen (arxiv:1307.7480, arxiv:140?.????) MIT/Perimeter Inst. 2014 @ APS March A Lattice
More informationWhat is a topological insulator? Ming-Che Chang Dept of Physics, NTNU
What is a topological insulator? Ming-Che Chang Dept of Physics, NTNU A mini course on topology extrinsic curvature K vs intrinsic (Gaussian) curvature G K 0 G 0 G>0 G=0 K 0 G=0 G
More informationV bg
SUPPLEMENTARY INFORMATION a b µ (1 6 cm V -1 s -1 ) 1..8.4-3 - -1 1 3 mfp (µm) 1 8 4-3 - -1 1 3 Supplementary Figure 1: Mobility and mean-free path. a) Drude mobility calculated from four-terminal resistance
More information2D Materials with Strong Spin-orbit Coupling: Topological and Electronic Transport Properties
2D Materials with Strong Spin-orbit Coupling: Topological and Electronic Transport Properties Artem Pulkin California Institute of Technology (Caltech), Pasadena, CA 91125, US Institute of Physics, Ecole
More informationSpin Hall and quantum spin Hall effects. Shuichi Murakami Department of Physics, Tokyo Institute of Technology PRESTO, JST
YKIS2007 (Kyoto) Nov.16, 2007 Spin Hall and quantum spin Hall effects Shuichi Murakami Department of Physics, Tokyo Institute of Technology PRESTO, JST Introduction Spin Hall effect spin Hall effect in
More informationWeyl fermions and the Anomalous Hall Effect
Weyl fermions and the Anomalous Hall Effect Anton Burkov CAP congress, Montreal, May 29, 2013 Outline Introduction: Weyl fermions in condensed matter, Weyl semimetals. Anomalous Hall Effect in ferromagnets
More informationIs the composite fermion a Dirac particle?
Is the composite fermion a Dirac particle? Dam T. Son (University of Chicago) Cold atoms meet QFT, 2015 Ref.: 1502.03446 Plan Plan Composite fermion: quasiparticle of Fractional Quantum Hall Effect (FQHE)
More informationIntroduction to topological insulators. Jennifer Cano
Introduction to topological insulators Jennifer Cano Adapted from Charlie Kane s Windsor Lectures: http://www.physics.upenn.edu/~kane/ Review article: Hasan & Kane Rev. Mod. Phys. 2010 What is an insulator?
More informationRecent developments in spintronic
Recent developments in spintronic Tomas Jungwirth nstitute of Physics ASCR, Prague University of Nottingham in collaboration with Hitachi Cambridge, University of Texas, Texas A&M University - Spintronics
More informationThe Superfluid Phase s of Helium 3
The Superfluid Phase s of Helium 3 DIETER VOLLHARD T Rheinisch-Westfälische Technische Hochschule Aachen, Federal Republic of German y PETER WÖLFL E Universität Karlsruhe Federal Republic of Germany PREFACE
More informationThree-terminal quantum-dot thermoelectrics
Three-terminal quantum-dot thermoelectrics Björn Sothmann Université de Genève Collaborators: R. Sánchez, A. N. Jordan, M. Büttiker 5.11.2013 Outline Introduction Quantum dots and Coulomb blockade Quantum
More informationSuperinsulator: a new topological state of matter
Superinsulator: a new topological state of matter M. Cristina Diamantini Nips laboratory, INFN and Department of Physics and Geology University of Perugia Coll: Igor Lukyanchuk, University of Picardie
More information