One-dimensional topological edge states of bismuth bilayers

Slides:

Advertisements

Similar presentations

Chiral Tunneling and the Klein Paradox in Graphene M. I. Katsnelson, K

Advertisements

Protected edge modes without symmetry Michael Levin University of Maryland.

Scanning tunnelling spectroscopy

Topological Insulators

Biexciton-Exciton Cascades in Graphene Quantum Dots CAP 2014, Sudbury Isil Ozfidan I.Ozfidan, M. Korkusinski,A.D.Guclu,J.McGuire and P.Hawrylak, PRB89,

Spintronics with topological insulator Takehito Yokoyama, Yukio Tanaka *, and Naoto Nagaosa Department of Applied Physics, University of Tokyo, Japan *

Exploring Topological Phases With Quantum Walks $$ NSF, AFOSR MURI, DARPA, ARO Harvard-MIT Takuya Kitagawa, Erez Berg, Mark Rudner Eugene Demler Harvard.

Aretouli E. Kleopatra 20/2/15 NCSR DEMOKRITOS, Athens, Greece

An Experimental Study and Fatigue Damage Model for Fretting Fatigue

PA4311 Quantum Theory of Solids Quantum Theory of Solids Mervyn Roy (S6) www2.le.ac.uk/departments/physics/people/mervynroy.

An Introduction to Graphene Electronic Structure

Influence of gases on the formation of atomic gold wires By using a Mechanically Controlled Break Junction (MCBJ) at 4.2 K it is possible to form atomic.

The Persistent Spin Helix Shou-Cheng Zhang, Stanford University Les Houches, June 2006.

Raman Spectrum of Graphene and Graphene layers PRL 97, (2006) Sebastian Remi Journal Club 11/26/2006.

Research fueled by: MRS Spring Meeting San Francisco April 28th 2011 JAIRO SINOVA Texas A&M University Institute of Physics ASCR Topological thermoelectrics.

Physics of Graphene A. M. Tsvelik. Graphene – a sheet of carbon atoms The spectrum is well described by the tight- binding Hamiltonian on a hexagonal.

Project topics due today. Next HW due in one week

Topological Insulators and Beyond

Computational Solid State Physics 計算物性学特論第４回 4. Electronic structure of crystals.

Carbon Nanotube Intramolecular Junctions. Nanotubes A graphene sheet with a hexagonal lattice…

Specific Heat of Solids Quantum Size Effect on the Specific Heat Electrical and Thermal Conductivities of Solids Thermoelectricity Classical Size Effect.

Multi-scale Heat Conduction Quantum Size Effect on the Specific Heat

Network for Computational Nanotechnology (NCN) UC Berkeley, Univ.of Illinois, Norfolk State, Northwestern, Purdue, UTEP Generation of Empirical Tight Binding.

Electronic Band Structures electrons in solids: in a periodic potential due to the periodic arrays of atoms electronic band structure: electron states.

Resonant medium: Up to four (Zn,Cd)Se quantum wells. Luminescence selection is possible with a variation of the Cd-content or the well width. The front.

Photonic Topological Insulators

UIC Physics Tessa Cooper Materials Science and Engineering Rutgers University Advisors: Dr. R. Klie and Q. Qiao Department of Physics, University of Illinois.

Drude weight and optical conductivity of doped graphene Giovanni Vignale, University of Missouri-Columbia, DMR The frequency of long wavelength.

Advanced methods of molecular dynamics 1.Monte Carlo methods 2.Free energy calculations 3.Ab initio molecular dynamics 4.Quantum molecular dynamics III.

The design of dielectric environment for ultra long lifetime of graphene plasmon Dr. Qing Dai 22/10/2015.

Electrons on the brink: Fractal patterns may be key to semiconductor magnetism Ali Yazdani, Princeton University, DMR Princeton-led team of scientists.

F. Sacconi, M. Povolotskyi, A. Di Carlo, P. Lugli University of Rome “Tor Vergata”, Rome, Italy M. Städele Infineon Technologies AG, Munich, Germany Full-band.

Last Time The# of allowed k states (dots) is equal to the number of primitive cells in the crystal.

Transverse optical mode for diatomic chain

Electrons in Solids Simplest Model: Free Electron Gas Quantum Numbers E,k Fermi “Surfaces” Beyond Free Electrons: Bloch’s Wave Function E(k) Band Dispersion.

Collin Broholm Johns Hopkins University and NIST Center for Neutron Research Quantum Phase Transition in Quasi-two-dimensional Frustrated Magnet M. A.

Theory of STM Imaging of Fullerene Peapods C.L. Kane and E.J. Mele D. Hornbaker, A. Yazdani, A.T. Johnson, D.E. Luzzi Tube states hybridize with C 60 orbitals.

Characterization of a Single Metal Impurity in Graphene Eric Cockayne Ceramics Division, NIST, Gaithersburg Gregory M. Rutter Joseph A. Stroscio Center.

Flat Band Nanostructures Vito Scarola

Topological Insulators

Collin Broholm Johns Hopkins University and NIST Center for Neutron Research Quantum Phase Transition in Quasi-two-dimensional Frustrated Magnet M. A.

Tunable excitons in gated graphene systems

A Versatile SLM Enabled Atomtronic Device for Quantum Simulation in 2D

of single-wall nanotube DNA hybrids

Introduction to topological insulators and STM/S on TIs

Spin-orbit interaction in a dual gated InAs/GaSb quantum well

Light propagation in topological two-level structures

Module A-4 Molecular Electronics

Topological Insulators

Band structure: Semiconductor

Volume 2, Issue 3, Pages (March 2017)

Nonequilibrium Green’s Function with Electron-Phonon Interactions

Tunneling between helical edge states through extended contacts

First principles calculation on field emission of boron/nitrogen doped carbon nanotube I’m going to talk about the first principles calculation on field.

Carbon Nanotube Diode Design

Study and Modification of the Graphene-Hydrogen adsorption barrier

Covalent Properties Main Concept:

Correlations of Electrons in Magnetic Fields

Landau Quantization and Quasiparticle Interference in the

Majorana Spin Diagnostics

Optical signature of topological insulator

Nonlinear response of gated graphene in a strong radiation field

Fig. 3 Realization of the Su-Schrieffer-Heeger (SSH) model.

Quasiparticle interference of the Fermi arcs and surface-bulk connectivity of a Weyl semimetal by Hiroyuki Inoue, András Gyenis, Zhijun Wang, Jian Li,

American Physical Society

Deformation of the Fermi surface in the

Scattering and Interference in Epitaxial Graphene

Observation of Majorana fermions in a ferromagnetic chains on a superconductor Princeton Center for Complex Materials (DMR ) Stevan Nadj-Perge,

Fig. 3 Realization of the Su-Schrieffer-Heeger (SSH) model.

Bulk-boundary correspondence and topological nontrivial nature of TaP

Presentation transcript:

One-dimensional topological edge states of bismuth bilayers Author: Iiya K. Drozdov, A. Alexandradinata, Sangjun Jeon, Stevan Nadj-Perge, Huiwen Ji, R. J. Cava, B. Andrei Bernevig and Ali Yazdani Present: Yuqin Sophia Duan

Background Quantum Spin Hall Effect Bi bilayer vs. graphene Top View Quantum Spin Hall Effect Bi bilayer vs. graphene Strong spin-orbit coupling Side View

motivation Conductance: only showed by semiconducting heterostructures in the topological phase Experiments on Bi suffered from an irregular structure of their edges

Experiment Single Bi crystal growth using the Bridgeman method STM Measurement Atomic structure of Bi-bilayer in (111) plane

experiment Simulation: Hybridization calculation of edges based on Liu-Allen model & ab initio1 Type-A edge has less bonds with the substrate; Type-B has direct hoppings to the substrate

Stm measurement

conductivity dI/dV spectra were acquired using a lock-in amplifier at f = 757 Hz. Type A show clear signature of 1D edge state, next we will look at its connection to the bulk electronic state of Bi bilayer.

Conclusion: Propagating 1D edge state is similar to the prediction for free-standing Bi bi-layer. To determine whether the 1D edge states have the predicted topological properties of free-standing Bi bilayer, they further examine the scattering properties. STM maps obtained along a line perpendicular to the edge & along the edge

Scattering properties The topological nature of the two edge modes, reflected in their spin properties allow scattering only between the states of similar spin Spatial 1D Fourier transform of the conductance map along the type A atomic step edge Wavefactors q = kf – k1

Dispersion and spin texture Spin expectation values for the top branch are plotted as a function of momentum. Employ Liu-Allen tight-binding model, but with a self-consistent Hartree term

Summary Strong suppression of the backscattering wavevector q* Experimentally characterized properties of q1 scattering channel Model calculation for a Bi bilayer Type A zigzag edges behave in a manner similar to free-standing Bi-bilayer quantum spin Hall system