The effect of dilute magnetic doping of a topological insulator on the surface states

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.

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

New Journal of Physics ◽

10.1088/1367-2630/16/6/065016 ◽

2014 ◽

Vol 16 (6) ◽

pp. 065016 ◽

Cited By ~ 7

Author(s):

K Miyamoto ◽

T Okuda ◽

M Nurmamat ◽

M Nakatake ◽

H Namatame ◽

...

Keyword(s):

Topological Insulator ◽

Surface States ◽

Rashba Effect ◽

Effect Of Surface

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

Nano Letters ◽

10.1021/acs.nanolett.6b04313 ◽

2017 ◽

Vol 17 (2) ◽

pp. 980-984 ◽

Cited By ~ 15

Author(s):

Yinming Shao ◽

Kirk W. Post ◽

Jhih-Sheng Wu ◽

Siyuan Dai ◽

Alex J. Frenzel ◽

...

Keyword(s):

Topological Insulator ◽

Faraday Rotation ◽

Surface States

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Induced unconventional superconductivity on the surface states of Bi2Te3 topological insulator

Nature Communications ◽

10.1038/s41467-017-02069-z ◽

2017 ◽

Vol 8 (1) ◽

Cited By ~ 22

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.

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

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/aadad7 ◽

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

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

Physical Review B ◽

10.1103/physrevb.105.035122 ◽

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

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Exceptional topological insulators

Nature Communications ◽

10.1038/s41467-021-25947-z ◽

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.

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