Dynamic Opening of a Gap in Dirac Surface States of the Thin-Film 3D Topological Insulator Bi2Se3 Driven by the Dynamic Rashba Effect

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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Anomalous Rashba Effect of Bi Thin Film Studied by Spin-Resolved ARPES

Modern Technologies for Creating the Thin-film Systems and Coatings ◽

10.5772/66278 ◽

2017 ◽

Cited By ~ 1

Author(s):

Akari Takayama

Keyword(s):

Thin Film ◽

Rashba Effect

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Electromagnetic waves in a topological insulator thin film stack: helicon-like wave mode and photonic band structure

Optics Express ◽

10.1364/oe.21.021317 ◽

2013 ◽

Vol 21 (18) ◽

pp. 21317

Author(s):

Jun-ichi Inoue

Keyword(s):

Thin Film ◽

Band Structure ◽

Topological Insulator ◽

Electromagnetic Waves ◽

Wave Mode ◽

Photonic Band Structure ◽

Photonic Band

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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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