Energy Spectrum and Broken spin-surface locking in Topological Insulator quantum dots
|
|
- Brook Boyd
- 5 years ago
- Views:
Transcription
1 Energy Spectrum and Broken spin-surface locking in Topological Insulator quantum dots A. Kundu 1 1 Heinrich-Heine Universität Düsseldorf, Germany The Capri Spring School on Transport in Nanostructures 2011 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 1 / 10
2 Introduction Outline Outline Introduction Quantum dot spectrum and spin structure (surface) Dirac Fermion theory on the surface Tight binding approach Summary A. Kundu, A. Zazunov, A. Levy Yeyati, T. Martin & R. Egger, Phys Rev B 83, (2011) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 2 / 10
3 Introduction Motivation Introduction Strong spin-orbit coupling and band inversion conspire to produce a time-reversal invariant topological insulator phase in meterials like Bi 2 Se 3 which has a bulk gap b 0.3 ev. Xia et all, Nature Physics (2009) 1 The measured spin texture of the surface is consistent with predictions obtained from 2D massless Dirac fermions. 2 The surface state is stable under weak TR invariant disorders. 3 The spin-momentum is locked on the surface. D. Hsieh et al, Nature 2009 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 3 / 10
4 Introduction Motivation Introduction Strong spin-orbit coupling and band inversion conspire to produce a time-reversal invariant topological insulator phase in meterials like Bi 2 Se 3 which has a bulk gap b 0.3 ev. Xia et all, Nature Physics (2009) 1 The measured spin texture of the surface is consistent with predictions obtained from 2D massless Dirac fermions. 2 The surface state is stable under weak TR invariant disorders. 3 The spin-momentum is locked on the surface. D. Hsieh et al, Nature 2009 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 3 / 10
5 Zhang et al, Nature Phys 5, 438 (2009) and Liu et al, PRB 82, (2010) H b = ɛ 0 σ 0 τ 0 + M k σ 0 τ z + [A 0 (k x σ x + k y σ y ) + B 0 kσ z ]τ x (1) This also defines the fermi velocities v 1 = B 0 and v 2 = A 0 in x y plane and along z axis. σ and τ acts on spin and orbital space to give rise spin-parity structure for the eigen state of the Hamiltonin. For cylindrically symmetric geometry: we have the conserved angular momenta: J = i φ + σ z /2 (2) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 4 / 10
6 Zhang et al, Nature Phys 5, 438 (2009) and Liu et al, PRB 82, (2010) H b = ɛ 0 σ 0 τ 0 + M k σ 0 τ z + [A 0 (k x σ x + k y σ y ) + B 0 kσ z ]τ x (1) This also defines the fermi velocities v 1 = B 0 and v 2 = A 0 in x y plane and along z axis. σ and τ acts on spin and orbital space to give rise spin-parity structure for the eigen state of the Hamiltonin. For cylindrically symmetric geometry: we have the conserved angular momenta: J = i φ + σ z /2 (2) σ r,φ,z = ê r,φ,z. σ Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 4 / 10
7 Dispersion relation of surface states: E j,± (k) = ± (v 1 k) 2 + (jv 2 /R) 2 And a gap in the spectrum which is 1/R Spin is locked with the surface σ r = 0 Egger et al, PRL (2010) Finite semiconductor nanowire/ carbon nanotube experiments are successfull Nygard et all, Nature (2000), Postma et all, Science (2001) Nontrivial spin connection in spherical TI Parente et all, arxiv: New feature may arise due to sharp (non-differential) egdes, for eg. in cylindrical geometry Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 5 / 10
8 Dispersion relation of surface states: E j,± (k) = ± (v 1 k) 2 + (jv 2 /R) 2 And a gap in the spectrum which is 1/R Spin is locked with the surface σ r = 0 Egger et al, PRL (2010) Finite semiconductor nanowire/ carbon nanotube experiments are successfull Nygard et all, Nature (2000), Postma et all, Science (2001) Nontrivial spin connection in spherical TI Parente et all, arxiv: New feature may arise due to sharp (non-differential) egdes, for eg. in cylindrical geometry Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 5 / 10
9 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
10 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
11 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
12 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
13 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
14 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
15 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Spin surface locking breaking reported previously Fu, PRL (2009) & Yazyev, Moore, Louie, PRL (2010) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
16 For finite length cylinder : m = j σ/2 ψ j,ν,n,σ,τ = 2/V sin[nπ(z/l 1/2)]e imφ J m(γ m/r ) J m+1 (γ mν ) η τ χ σ (3) Kramers degeneracy j j k n nπ/l additional n = 0 states emerges one for valence band and one for conduction band for j > 1/2, a pair of subgap states inside the gap s. σ φ = 0 and σ r 0 Spin surface locking breaking reported previously Fu, PRL (2009) & Yazyev, Moore, Louie, PRL (2010) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 6 / 10
17 Surface Dirac fermion Theory Surface Dirac fermion Theory [ v 1 σ φ ( i z ) v 2 ] τ z H D = R σ zj ( H c = v 2 [ i r + 1 ) σ r + J ] 2r R σ φ τ x H D = [ v 1 σ φ ( i z ) v2 R σ zj ] ˆτ the operator ˆτ can be determined from symmetries of the Hamiltonian, namely azimuthal symmetry, time reversal symmetry & inversion symmetry. H = H D (φ, z)δ(r R) + H cap (r, φ) s=± δ(z sl/2) (4) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 7 / 10
18 Surface Dirac fermion Theory Surface Dirac fermion Theory [ v 1 σ φ ( i z ) v 2 ] τ z H D = R σ zj ( H c = v 2 [ i r + 1 ) σ r + J ] 2r R σ φ τ x H D = [ v 1 σ φ ( i z ) v2 R σ zj ] ˆτ the operator ˆτ can be determined from symmetries of the Hamiltonian, namely azimuthal symmetry, time reversal symmetry & inversion symmetry. H = H D (φ, z)δ(r R) + H cap (r, φ) s=± δ(z sl/2) (4) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 7 / 10
19 Surface Dirac fermion Theory which gives the energy quantisation: On the surface of the cap, we obtain E n,j,± = ± (πnv 1 /L) 2 + (jv 2 /R) 2 (5) σ φ = 0 σ r 0 For each total angular momentum j, there are two zero-momentum states corresponding to conduction and valence band, respectively. For the physically allowed k = 0 we find spatially uniform densities. Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 8 / 10
20 Tight Binding Approach Tight Binding Model A simple microscopic model for strong TI was previously proposed by Fu, Kane, Mele PRL (2007) H tb = <i,j> t ij c i c j + 4iλ so a 2 We observe sub gap states as from the low energy model As similar to both the previous predictions, we observe < σ φ >= 0, < σ r > 0 (7) Also, note that, for infinite nanowire, TB calculations give < σ r >= 0. <<i,j>> c i ( σ).[ d 1 ij d 2 ij ]c j (6) Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 9 / 10
21 Summary Summary All three approaches shows that the spin surface locking is broken due to the presence of such edges. A nontrivial eigenstate with k = n = 0. In such a zero-momentum state the charge and spin densities along the trunk are basically homogeneous. The finite-length nanowire dot has subgap states when electron-hole symmetry is broken. The wavefunction of such a subgap state is localized on both caps simultaneously. It may be interesting to observe the effect of coulomb interactions and applied magnetic field Arijit Kundu (Heinrich-Heine University) Topological Insulator quantum dot 10 / 10
Electronic transport in topological insulators
Electronic transport in topological insulators Reinhold Egger Institut für Theoretische Physik, Düsseldorf Alex Zazunov, Alfredo Levy Yeyati Trieste, November 011 To the memory of my dear friend Please
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 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 informationIntroductory lecture on topological insulators. Reza Asgari
Introductory lecture on topological insulators Reza Asgari Workshop on graphene and topological insulators, IPM. 19-20 Oct. 2011 Outlines -Introduction New phases of materials, Insulators -Theory quantum
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 informationDisordered topological insulators with time-reversal symmetry: Z 2 invariants
Keio Topo. Science (2016/11/18) Disordered topological insulators with time-reversal symmetry: Z 2 invariants Hosho Katsura Department of Physics, UTokyo Collaborators: Yutaka Akagi (UTokyo) Tohru Koma
More informationDirac-Fermion-Induced Parity Mixing in Superconducting Topological Insulators. Nagoya University Masatoshi Sato
Dirac-Fermion-Induced Parity Mixing in Superconducting Topological Insulators Nagoya University Masatoshi Sato In collaboration with Yukio Tanaka (Nagoya University) Keiji Yada (Nagoya University) Ai Yamakage
More informationARPES experiments on 3D topological insulators. Inna Vishik Physics 250 (Special topics: spectroscopies of quantum materials) UC Davis, Fall 2016
ARPES experiments on 3D topological insulators Inna Vishik Physics 250 (Special topics: spectroscopies of quantum materials) UC Davis, Fall 2016 Outline Using ARPES to demonstrate that certain materials
More informationPOEM: Physics of Emergent Materials
POEM: Physics of Emergent Materials Nandini Trivedi L1: Spin Orbit Coupling L2: Topology and Topological Insulators Reference: Bernevig Topological Insulators and Topological Superconductors Tutorials:
More informationTopological Insulators
Topological Insulators A new state of matter with three dimensional topological electronic order L. Andrew Wray Lawrence Berkeley National Lab Princeton University Surface States (Topological Order in
More informationVortex States in a Non-Abelian Magnetic Field
Vortex States in a Non-Abelian Magnetic Field Predrag Nikolić George Mason University Institute for Quantum Matter @ Johns Hopkins University SESAPS November 10, 2016 Acknowledgments Collin Broholm IQM
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 informationTopological Kondo Insulators!
Topological Kondo Insulators! Maxim Dzero, University of Maryland Collaborators: Kai Sun, University of Maryland Victor Galitski, University of Maryland Piers Coleman, Rutgers University Main idea Kondo
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 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 informationProtection of the surface states of a topological insulator: Berry phase perspective
Protection of the surface states of a topological insulator: Berry phase perspective Ken-Ichiro Imura Hiroshima University collaborators: Yositake Takane Tomi Ohtsuki Koji Kobayashi Igor Herbut Takahiro
More informationSpin-Orbit Interactions in Semiconductor Nanostructures
Spin-Orbit Interactions in Semiconductor Nanostructures Branislav K. Nikolić Department of Physics and Astronomy, University of Delaware, U.S.A. http://www.physics.udel.edu/~bnikolic Spin-Orbit Hamiltonians
More informationLCI -birthplace of liquid crystal display. May, protests. Fashion school is in top-3 in USA. Clinical Psychology program is Top-5 in USA
LCI -birthplace of liquid crystal display May, 4 1970 protests Fashion school is in top-3 in USA Clinical Psychology program is Top-5 in USA Topological insulators driven by electron spin Maxim Dzero Kent
More informationSurface Majorana Fermions in Topological Superconductors. ISSP, Univ. of Tokyo. Nagoya University Masatoshi Sato
Surface Majorana Fermions in Topological Superconductors ISSP, Univ. of Tokyo Nagoya University Masatoshi Sato Kyoto Tokyo Nagoya In collaboration with Satoshi Fujimoto (Kyoto University) Yoshiro Takahashi
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 insulator with time-reversal symmetry
Phys620.nb 101 7 Topological insulator with time-reversal symmetry Q: Can we get a topological insulator that preserves the time-reversal symmetry? A: Yes, with the help of the spin degree of freedom.
More informationSpin orbit interaction in graphene monolayers & carbon nanotubes
Spin orbit interaction in graphene monolayers & carbon nanotubes Reinhold Egger Institut für Theoretische Physik, Düsseldorf Alessandro De Martino Andreas Schulz, Artur Hütten MPI Dresden, 25.10.2011 Overview
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 informationTopological Insulators and Ferromagnets: appearance of flat surface bands
Topological Insulators and Ferromagnets: appearance of flat surface bands Thomas Dahm University of Bielefeld T. Paananen and T. Dahm, PRB 87, 195447 (2013) T. Paananen et al, New J. Phys. 16, 033019 (2014)
More informationNotes on Topological Insulators and Quantum Spin Hall Effect. Jouko Nieminen Tampere University of Technology.
Notes on Topological Insulators and Quantum Spin Hall Effect Jouko Nieminen Tampere University of Technology. Not so much discussed concept in this session: topology. In math, topology discards small details
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 informationTopological thermoelectrics
Topological thermoelectrics JAIRO SINOVA Texas A&M University Institute of Physics ASCR Oleg Tretiakov, Artem Abanov, Suichi Murakami Great job candidate MRS Spring Meeting San Francisco April 28th 2011
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 informationSymmetries in Quantum Transport : From Random Matrix Theory to Topological Insulators. Philippe Jacquod. U of Arizona
Symmetries in Quantum Transport : From Random Matrix Theory to Topological Insulators Philippe Jacquod U of Arizona UA Phys colloquium - feb 1, 2013 Continuous symmetries and conservation laws Noether
More informationKonstantin Y. Bliokh, Daria Smirnova, Franco Nori. Center for Emergent Matter Science, RIKEN, Japan. Science 348, 1448 (2015)
Konstantin Y. Bliokh, Daria Smirnova, Franco Nori Center for Emergent Matter Science, RIKEN, Japan Science 348, 1448 (2015) QSHE and topological insulators The quantum spin Hall effect means the presence
More informationWiring Topological Phases
1 Wiring Topological Phases Quantum Condensed Matter Journal Club Adhip Agarwala Department of Physics Indian Institute of Science adhip@physics.iisc.ernet.in February 4, 2016 So you are interested in
More informationCoupling of spin and orbital motion of electrons in carbon nanotubes
Coupling of spin and orbital motion of electrons in carbon nanotubes Kuemmeth, Ferdinand, et al. "Coupling of spin and orbital motion of electrons in carbon nanotubes." Nature 452.7186 (2008): 448. Ivan
More informationTOPOLOGY IN CONDENSED MATTER SYSTEMS: MAJORANA MODES AND WEYL SEMIMETALS. Jan 23, 2012, University of Illinois, Urbana-Chamapaign
TOPOLOGY IN CONDENSED MATTER SYSTEMS: MAJORANA MODES AND WEYL SEMIMETALS Pavan Hosur UC Berkeley Jan 23, 2012, University of Illinois, Urbana-Chamapaign Acknowledgements Advisor: Ashvin Vishwanath UC Berkeley
More informationCrystalline Symmetry and Topology. YITP, Kyoto University Masatoshi Sato
Crystalline Symmetry and Topology YITP, Kyoto University Masatoshi Sato In collaboration with Ken Shiozaki (YITP) Kiyonori Gomi (Shinshu University) Nobuyuki Okuma (YITP) Ai Yamakage (Nagoya University)
More informationTime Reversal Invariant Ζ 2 Topological Insulator
Time Reversal Invariant Ζ Topological Insulator D Bloch Hamiltonians subject to the T constraint 1 ( ) ΘH Θ = H( ) with Θ = 1 are classified by a Ζ topological invariant (ν =,1) Understand via Bul-Boundary
More informationHartmut Buhmann. Physikalisches Institut, EP3 Universität Würzburg Germany
Hartmut Buhmann Physikalisches Institut, EP3 Universität Würzburg Germany Part I and II Insulators and Topological Insulators HgTe crystal structure Part III quantum wells Two-Dimensional TI Quantum Spin
More informationarxiv: v1 [cond-mat.mes-hall] 29 Jul 2010
Discovery of several large families of Topological Insulator classes with backscattering-suppressed spin-polarized single-dirac-cone on the surface arxiv:1007.5111v1 [cond-mat.mes-hall] 29 Jul 2010 Su-Yang
More informationFirst-Principles Calculation of Topological Invariants (Wannier Functions Approach) Alexey A. Soluyanov
First-Principles Calculation of Topological Invariants (Wannier Functions Approach) Alexey A. Soluyanov ES'12, WFU, June 8, 212 The present work was done in collaboration with David Vanderbilt Outline:
More informationMesoscopic physics: From low-energy nuclear [1] to relativistic [2] high-energy analogies
Mesoscopic physics: From low-energy nuclear [1] to relativistic [2] high-energy analogies Constantine Yannouleas and Uzi Landman School of Physics, Georgia Institute of Technology [1] Ch. 4 in Metal Clusters,
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 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 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 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 informationLocal currents in a two-dimensional topological insulator
Local currents in a two-dimensional topological insulator Xiaoqian Dang, J. D. Burton and Evgeny Y. Tsymbal Department of Physics and Astronomy Nebraska Center for Materials and Nanoscience University
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 informationSUPPLEMENTARY INFORMATION
A Dirac point insulator with topologically non-trivial surface states D. Hsieh, D. Qian, L. Wray, Y. Xia, Y.S. Hor, R.J. Cava, and M.Z. Hasan Topics: 1. Confirming the bulk nature of electronic bands by
More informationMajorana single-charge transistor. Reinhold Egger Institut für Theoretische Physik
Majorana single-charge transistor Reinhold Egger Institut für Theoretische Physik Overview Coulomb charging effects on quantum transport through Majorana nanowires: Two-terminal device: Majorana singlecharge
More informationVisualizing Electronic Structures of Quantum Materials By Angle Resolved Photoemission Spectroscopy (ARPES)
Visualizing Electronic Structures of Quantum Materials By Angle Resolved Photoemission Spectroscopy (ARPES) PART A: ARPES & Application Yulin Chen Oxford University / Tsinghua University www.arpes.org.uk
More informationSymmetric Surfaces of Topological Superconductor
Symmetric Surfaces of Topological Superconductor Sharmistha Sahoo Zhao Zhang Jeffrey Teo Outline Introduction Brief description of time reversal symmetric topological superconductor. Coupled wire model
More informationTopological Photonics with Heavy-Photon Bands
Topological Photonics with Heavy-Photon Bands Vassilios Yannopapas Dept. of Physics, National Technical University of Athens (NTUA) Quantum simulations and many-body physics with light, 4-11/6/2016, Hania,
More informationUnconventional pairing in three-dimensional topological insulators with warped surface state Andrey Vasenko
Unconventional pairing in three-dimensional topological insulators with warped surface state Andrey Vasenko Moscow Institute of Electronics and Mathematics, Higher School of Economics Collaborators Alexander
More informationTopological Bandstructures for Ultracold Atoms
Topological Bandstructures for Ultracold Atoms Nigel Cooper Cavendish Laboratory, University of Cambridge New quantum states of matter in and out of equilibrium GGI, Florence, 12 April 2012 NRC, PRL 106,
More informationDirac semimetal in three dimensions
Dirac semimetal in three dimensions Steve M. Young, Saad Zaheer, Jeffrey C. Y. Teo, Charles L. Kane, Eugene J. Mele, and Andrew M. Rappe University of Pennsylvania 6/7/12 1 Dirac points in Graphene Without
More informationUniversal transport at the edge: Disorder, interactions, and topological protection
Universal transport at the edge: Disorder, interactions, and topological protection Matthew S. Foster, Rice University March 31 st, 2016 Universal transport coefficients at the edges of 2D topological
More informationStructure and Topology of Band Structures in the 1651 Magnetic Space Groups
Structure and Topology of Band Structures in the 1651 Magnetic Space Groups Haruki Watanabe University of Tokyo [Noninteracting] Sci Adv (2016) PRL (2016) Nat Commun (2017) (New) arxiv:1707.01903 [Interacting]
More informationTopological insulators
http://www.physik.uni-regensburg.de/forschung/fabian Topological insulators Jaroslav Fabian Institute for Theoretical Physics University of Regensburg Stara Lesna, 21.8.212 DFG SFB 689 what are 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 informationQuantum Spin Hall Effect in Graphene
Quantum Spin Hall Effect in Graphene Taylor S., Kai S., Benjamin S., Kathryn W., Penghao Z. C. L. Kane and E. J. Mele, Phys. Rev. Lett. 95, 226801 -- (2005) Quick Overview First the Motivation. Go over
More informationVortices and vortex states of Rashba spin-orbit coupled condensates
Vortices and vortex states of Rashba spin-orbit coupled condensates Predrag Nikolić George Mason University Institute for Quantum Matter @ Johns Hopkins University March 5, 2014 P.N, T.Duric, Z.Tesanovic,
More informationLoop current order in optical lattices
JQI Summer School June 13, 2014 Loop current order in optical lattices Xiaopeng Li JQI/CMTC Outline Ultracold atoms confined in optical lattices 1. Why we care about lattice? 2. Band structures and Berry
More informationProximity-induced magnetization dynamics, interaction effects, and phase transitions on a topological surface
Proximity-induced magnetization dynamics, interaction effects, and phase transitions on a topological surface Ilya Eremin Theoretische Physik III, Ruhr-Uni Bochum Work done in collaboration with: F. Nogueira
More informationFrom graphene to Z2 topological insulator
From graphene to Z2 topological insulator single Dirac topological AL mass U U valley WL ordinary mass or ripples WL U WL AL AL U AL WL Rashba Ken-Ichiro Imura Condensed-Matter Theory / Tohoku Univ. Dirac
More informationUltrafast study of Dirac fermions in out of equilibrium Topological Insulators
Ultrafast study of Dirac fermions in out of equilibrium Topological Insulators Marino Marsi Laboratoire de Physique des Solides CNRS Univ. Paris-Sud - Université Paris-Saclay IMPACT, Cargèse, August 26
More informationteam Hans Peter Büchler Nicolai Lang Mikhail Lukin Norman Yao Sebastian Huber
title 1 team 2 Hans Peter Büchler Nicolai Lang Mikhail Lukin Norman Yao Sebastian Huber motivation: topological states of matter 3 fermions non-interacting, filled band (single particle physics) topological
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 informationBuilding Frac-onal Topological Insulators. Collaborators: Michael Levin Maciej Kosh- Janusz Ady Stern
Building Frac-onal Topological Insulators Collaborators: Michael Levin Maciej Kosh- Janusz Ady Stern The program Background: Topological insulators Frac-onaliza-on Exactly solvable Hamiltonians for frac-onal
More informationASHVIN VISHWANATH HARVARD UNIVERSITY, USA.
BOULDER SUMMER SCHOOL LECTURE NOTES TOPOLOGICAL SEMIMETALS AND SYMMETRY PROTECTED TOPOLOGICAL PHASES ASHVIN VISHWANATH HARVARD UNIVERSITY, USA. In the previous lectures you have heard about topological
More informationElectron Interactions and Nanotube Fluorescence Spectroscopy C.L. Kane & E.J. Mele
Electron Interactions and Nanotube Fluorescence Spectroscopy C.L. Kane & E.J. Mele Large radius theory of optical transitions in semiconducting nanotubes derived from low energy theory of graphene Phys.
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 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 informationMn in GaAs: from a single impurity to ferromagnetic layers
Mn in GaAs: from a single impurity to ferromagnetic layers Paul Koenraad Department of Applied Physics Eindhoven University of Technology Materials D e v i c e s S y s t e m s COBRA Inter-University Research
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 informationSpinon magnetic resonance. Oleg Starykh, University of Utah
Spinon magnetic resonance Oleg Starykh, University of Utah May 17-19, 2018 Examples of current literature 200 cm -1 = 6 THz Spinons? 4 mev = 1 THz The big question(s) What is quantum spin liquid? No broken
More informationInteractions and transport in Majorana wires. Alfredo Levy Yeyati
Interactions and transport in Majorana wires Alfredo Levy Yeyati SPICE Workshop: Spin dynamics in the Dirac systems, Mainz 6-9 June 2017 Content Low energy transport theory in Majorana wire junctions,
More informationQuantum phase transitions of insulators, superconductors and metals in two dimensions
Quantum phase transitions of insulators, superconductors and metals in two dimensions Talk online: sachdev.physics.harvard.edu HARVARD Outline 1. Phenomenology of the cuprate superconductors (and other
More informationHIGHER INVARIANTS: TOPOLOGICAL INSULATORS
HIGHER INVARIANTS: TOPOLOGICAL INSULATORS Sponsoring This material is based upon work supported by the National Science Foundation Grant No. DMS-1160962 Jean BELLISSARD Georgia Institute of Technology,
More informationComposite Dirac liquids
Composite Dirac liquids Composite Fermi liquid non-interacting 3D TI surface Interactions Composite Dirac liquid ~ Jason Alicea, Caltech David Mross, Andrew Essin, & JA, Physical Review X 5, 011011 (2015)
More informationManipulation of Majorana fermions via single charge control
Manipulation of Majorana fermions via single charge control Karsten Flensberg Niels Bohr Institute University of Copenhagen Superconducting hybrids: from conventional to exotic, Villard de Lans, France,
More informationInterband effects and orbital suceptibility of multiband tight-binding models
Interband effects and orbital suceptibility of multiband tight-binding models Frédéric Piéchon LPS (Orsay) with A. Raoux, J-N. Fuchs and G. Montambaux Orbital suceptibility Berry curvature ky? kx GDR Modmat,
More informationSymmetry Protected Topological Insulators and Semimetals
Symmetry Protected Topological Insulators and Semimetals I. Introduction : Many examples of topological band phenomena II. Recent developments : - Line node semimetal Kim, Wieder, Kane, Rappe, PRL 115,
More informationMajorana Fermions in Superconducting Chains
16 th December 2015 Majorana Fermions in Superconducting Chains Matilda Peruzzo Fermions (I) Quantum many-body theory: Fermions Bosons Fermions (II) Properties Pauli exclusion principle Fermions (II)
More informationQuantum Hall effect. Quantization of Hall resistance is incredibly precise: good to 1 part in I believe. WHY?? G xy = N e2 h.
Quantum Hall effect V1 V2 R L I I x = N e2 h V y V x =0 G xy = N e2 h n.b. h/e 2 = 25 kohms Quantization of Hall resistance is incredibly precise: good to 1 part in 10 10 I believe. WHY?? Robustness Why
More informationTransport through interacting Majorana devices. Reinhold Egger Institut für Theoretische Physik
Transport through interacting Maorana devices Reinhold Egger Institut für Theoretische Physik Overview Coulomb charging effects on quantum transport through Maorana nanowires: Two-terminal device: Maorana
More informationWeyl semimetals and topological phase transitions
Weyl semimetals and topological phase transitions Shuichi Murakami 1 Department of Physics, Tokyo Institute of Technology 2 TIES, Tokyo Institute of Technology 3 CREST, JST Collaborators: R. Okugawa (Tokyo
More informationTime-Reversal Symmetric Two-Dimensional Topological Insulators: The Bernevig-Hughes-Zhang Model
Time-Reversal Symmetric Two-Dimensional Topological Insulators: The Bernevig-Hughes-Zhang Model Alexander Pearce Intro to Topological Insulators: Week 5 November 26, 2015 1 / 22 This notes are based on
More informationLecture notes on topological insulators
Lecture notes on topological insulators Ming-Che Chang Department of Physics, National Taiwan Normal University, Taipei, Taiwan (Dated: November 1, 18) Contents I. D Topological insulator 1 A. General
More informationE E F (ev) (a) (a) (b) (c) (d) (A ) (A ) M
Pis'ma v ZhET, vol. 96, iss. 12, pp. 870 { 874 c 2012 December 25 New topological surface state in layered topological insulators: unoccupied Dirac cone S. V. Eremeev +1), I. V. Silkin, T. V. Menshchikova,
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 informationTopological Insulator Surface States and Electrical Transport. Alexander Pearce Intro to Topological Insulators: Week 11 February 2, / 21
Topological Insulator Surface States and Electrical Transport Alexander Pearce Intro to Topological Insulators: Week 11 February 2, 2017 1 / 21 This notes are predominately based on: J.K. Asbóth, L. Oroszlány
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 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 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 informationarxiv: v1 [cond-mat.supr-con] 17 Dec 2009
Odd-Parity Topological Superconductors: Theory and Application to Cu x Bi Se 3 Liang Fu and Erez Berg Department of Physics, Harvard University, Cambridge, MA 0138 arxiv:091.394v1 [cond-mat.supr-con] 17
More informationTransport through Andreev Bound States in a Superconductor-Quantum Dot-Graphene System
Transport through Andreev Bound States in a Superconductor-Quantum Dot-Graphene System Nadya Mason Travis Dirk, Yung-Fu Chen, Cesar Chialvo Taylor Hughes, Siddhartha Lal, Bruno Uchoa Paul Goldbart University
More informationRecent developments in topological materials
Recent developments in topological materials NHMFL Winter School January 6, 2014 Joel Moore University of California, Berkeley, and Lawrence Berkeley National Laboratory Berkeley students: Andrew Essin,
More informationTopological insulator gap in graphene with heavy adatoms
Topological insulator gap in graphene with heavy adatoms ES2013, College of William and Mary Ruqian Wu Department of Physics and Astronomy, University of California, Irvine, California 92697 Supported
More informationElectrons in a periodic potential
Chapter 3 Electrons in a periodic potential 3.1 Bloch s theorem. We consider in this chapter electrons under the influence of a static, periodic potential V (x), i.e. such that it fulfills V (x) = V (x
More informationMajorana-type quasiparticles in nanoscopic systems
Kraków, 20 IV 2015 Majorana-type quasiparticles in nanoscopic systems Tadeusz Domański / UMCS, Lublin / Kraków, 20 IV 2015 Majorana-type quasiparticles in nanoscopic systems Tadeusz Domański / UMCS, Lublin
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 informationElectronic structure of correlated electron systems. G.A.Sawatzky UBC Lecture
Electronic structure of correlated electron systems G.A.Sawatzky UBC Lecture 6 011 Influence of polarizability on the crystal structure Ionic compounds are often cubic to maximize the Madelung energy i.e.
More information