scholarly journals Experimental signature of a topological quantum dot

Nanoscale ◽  
2020 ◽  
Vol 12 (44) ◽  
pp. 22817-22825
Author(s):  
Marie S. Rider ◽  
Maria Sokolikova ◽  
Stephen M. Hanham ◽  
Miguel Navarro-Cía ◽  
Peter D. Haynes ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Topological Insulator ◽  
Surface States ◽  
Topological Quantum

Topological insulator nanoparticles (TINPs) host topologically protected Dirac surface states, just like their bulk counterparts.

scholarly journals In-plane magnetic field-driven symmetry breaking in topological insulator-based three-terminal junctions

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jonas Kölzer ◽  
Kristof Moors ◽  
Abdur Rehman Jalil ◽  
Erik Zimmermann ◽  
Daniel Rosenbach ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Topological Insulator ◽  
Three Dimensional ◽  
Surface States ◽  
Output Terminal ◽  
Current Switch ◽  
Topological Quantum ◽  
Orbital Effect ◽  
Topological Surface ◽  
Topological Quantum Computation

AbstractTopological surface states of three-dimensional topological insulator nanoribbons and their distinct magnetoconductance properties are promising for topoelectronic applications and topological quantum computation. A crucial building block for nanoribbon-based circuits are three-terminal junctions. While the transport of topological surface states on a planar boundary is not directly affected by an in-plane magnetic field, the orbital effect cannot be neglected when the surface states are confined to the boundary of a nanoribbon geometry. Here, we report on the magnetotransport properties of such three-terminal junctions. We observe a dependence of the current on the in-plane magnetic field, with a distinct steering pattern of the surface state current towards a preferred output terminal for different magnetic field orientations. We demonstrate that this steering effect originates from the orbital effect, trapping the phase-coherent surface states in the different legs of the junction on opposite sides of the nanoribbon and breaking the left-right symmetry of the transmission across the junction. The reported magnetotransport properties demonstrate that an in-plane magnetic field is not only relevant but also very useful for the characterization and manipulation of transport in three-dimensional topological insulator nanoribbon-based junctions and circuits, acting as a topoelectric current switch.

scholarly journals Many-impurity scattering on the surface of a topological insulator

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Luis Hernando ◽  
Yuriko Baba ◽  
Elena Díaz ◽  
Francisco Domínguez-Adame
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Topological Insulator ◽  
Disordered Systems ◽  
Spectral Properties ◽  
Random Distribution ◽  
Surface States ◽  
Impurity Scattering ◽  
Self Consistent ◽  
The Impact

AbstractWe theoretically address the impact of a random distribution of non-magnetic impurities on the electron states formed at the surface of a topological insulator. The interaction of electrons with the impurities is accounted for by a separable pseudo-potential method that allows us to obtain closed expressions for the density of states. Spectral properties of surface states are assessed by means of the Green’s function averaged over disorder realisations. For comparison purposes, the configurationally averaged Green’s function is calculated by means of two different self-consistent methods, namely the self-consistent Born approximation (SCBA) and the coherent potential approximation (CPA). The latter is often regarded as the best single-site theory for the study of the spectral properties of disordered systems. However, although a large number of works employ the SCBA for the analysis of many-impurity scattering on the surface of a topological insulator, CPA studies of the same problem are scarce in the literature. In this work, we find that the SCBA overestimates the impact of the random distribution of impurities on the spectral properties of surface states compared to the CPA predictions. The difference is more pronounced when increasing the magnitude of the disorder.

scholarly journals TOPOLOGICAL INSULATOR AND THE DIRAC EQUATION

SPIN ◽  
2011 ◽  
Vol 01 (01) ◽  
pp. 33-44 ◽  
Author(s):  
SHUN-QING SHEN ◽  
WEN-YU SHAN ◽  
HAI-ZHOU LU
Keyword(s):  
Dirac Equation ◽  
Topological Insulator ◽  
Bound States ◽  
Topological Insulators ◽  
Mass Term ◽  
Point Of View ◽  
Quadratic Term ◽  
General Description ◽  
Dirac Equations ◽  
Topological Quantum

We present a general description of topological insulators from the point of view of Dirac equations. The Z2 index for the Dirac equation is always zero, and thus the Dirac equation is topologically trivial. After the quadratic term in momentum is introduced to correct the mass term m or the band gap of the Dirac equation, i.e., m → m − Bp2, the Z2 index is modified as 1 for mB > 0 and 0 for mB < 0. For a fixed B there exists a topological quantum phase transition from a topologically trivial system to a nontrivial system when the sign of mass m changes. A series of solutions near the boundary in the modified Dirac equation is obtained, which is characteristic of topological insulator. From the solutions of the bound states and the Z2 index we establish a relation between the Dirac equation and topological insulators.

scholarly journals The gigantic Rashba effect of surface states energetically buried in the topological insulator Bi2Te2Se

2014 ◽  
Vol 16 (6) ◽  
pp. 065016 ◽  
Author(s):  
K Miyamoto ◽  
T Okuda ◽  
M Nurmamat ◽  
M Nakatake ◽  
H Namatame ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Surface States ◽  
Rashba Effect ◽  
Effect Of Surface

scholarly journals Faraday Rotation Due to Surface States in the Topological Insulator (Bi1–xSbx)2Te3

Nano Letters ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 980-984 ◽  
Author(s):  
Yinming Shao ◽  
Kirk W. Post ◽  
Jhih-Sheng Wu ◽  
Siyuan Dai ◽  
Alex J. Frenzel ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Faraday Rotation ◽  
Surface States

scholarly journals Induced unconventional superconductivity on the surface states of Bi2Te3 topological insulator

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Sophie Charpentier ◽  
Luca Galletti ◽  
Gunta Kunakova ◽  
Riccardo Arpaia ◽  
Yuxin Song ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Topological Insulator ◽  
Quantum Interference ◽  
Order Parameter ◽  
Thermal Strain ◽  
Surface States ◽  
Field Pattern ◽  
Key Factors ◽  
Ordered Phases ◽  
Simultaneous Existence

Abstract Topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. The key ingredient is an unconventional order parameter, with an orbital component containing a chiral p x  + ip y wave term. Here we present phase-sensitive measurements, based on the quantum interference in nanoscale Josephson junctions, realized by using Bi2Te3 topological insulator. We demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral p x  + ip y component. The magnetic field pattern of the junctions shows a dip at zero externally applied magnetic field, which is an incontrovertible signature of the simultaneous existence of 0 and π coupling within the junction, inherent to a non trivial order parameter phase. The nano-textured morphology of the Bi2Te3 flakes, and the dramatic role played by thermal strain are the surprising key factors for the display of an unconventional induced order parameter.

Spin accumulation in topological insulator thin films—influence of bulk and topological surface states

2018 ◽  
Vol 51 (42) ◽  
pp. 425301
Author(s):  
Zhuo Bin Siu ◽  
Yi Wang ◽  
Hyunsoo Yang ◽  
Mansoor B A Jalil
Keyword(s):  
Thin Films ◽  
Topological Insulator ◽  
Surface States ◽  
Spin Accumulation ◽  
Topological Surface

scholarly journals Spectroscopic signature of surface states and bunching of bulk subbands in topological insulator ( Bi0.4Sb0.6)2Te3 thin films

2022 ◽  
Vol 105 (3) ◽  
Author(s):  
Liesbeth Mulder ◽  
Carolien Castenmiller ◽  
Femke J. Witmans ◽  
Steef Smit ◽  
Mark S. Golden ◽  
...  
Keyword(s):  
Thin Films ◽  
Topological Insulator ◽  
Surface States

scholarly journals Exceptional topological insulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Michael Denner ◽  
Anastasiia Skurativska ◽  
Frank Schindler ◽  
Mark H. Fischer ◽  
Ronny Thomale ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Three Dimensional ◽  
Surface States ◽  
Exceptional Point ◽  
Weyl Semimetal ◽  
Complex Eigenvalues ◽  
Topological State ◽  
Single Sheet ◽  
Bulk Energy ◽  
State Of Matter

AbstractWe introduce the exceptional topological insulator (ETI), a non-Hermitian topological state of matter that features exotic non-Hermitian surface states which can only exist within the three-dimensional topological bulk embedding. We show how this phase can evolve from a Weyl semimetal or Hermitian three-dimensional topological insulator close to criticality when quasiparticles acquire a finite lifetime. The ETI does not require any symmetry to be stabilized. It is characterized by a bulk energy point gap, and exhibits robust surface states that cover the bulk gap as a single sheet of complex eigenvalues or with a single exceptional point. The ETI can be induced universally in gapless solid-state systems, thereby setting a paradigm for non-Hermitian topological matter.

Sign in / Sign up

Export Citation Format

Share Document