Observation of a large-gap topological-insulator class with a single Dirac cone on the surface
Yuqi Xia,Dong Qian,Dong Qian,David Hsieh,Lewis Wray,Arijeet Pal,Hsin Lin,Arun Bansil,D. Grauer,Yew San Hor,Robert J. Cava,M. Z. Hasan +11 more
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TLDR
In this paper, an angle-resolved photo-emission spectroscopy study was conducted to reveal the first observation of a topological state of matter featuring a single surface Dirac cone realized in the naturally occurring Bi-2Se-3 class of materials.Abstract:
Recent experiments and theories have suggested that strong spin–orbit coupling effects in certain band insulators can give rise to a new phase of quantum matter, the so-called topological insulator, which can show macroscopic quantum-entanglement effects. Such systems feature two-dimensional surface states whose electrodynamic properties are described not by the conventional Maxwell equations but rather by an attached axion field, originally proposed to describe interacting quarks. It has been proposed that a topological insulator with a single Dirac cone interfaced with a superconductor can form the most elementary unit for performing fault-tolerant quantum computation. Here we present an angle-resolved photoemission spectroscopy study that reveals the first observation of such a topological state of matter featuring a single surface Dirac cone realized in the naturally occurring Bi_2Se_3 class of materials. Our results, supported by our theoretical calculations, demonstrate that undoped Bi_2Se_3 can serve as the parent matrix compound for the long-sought topological device where in-plane carrier transport would have a purely quantum topological origin. Our study further suggests that the undoped compound reached via n-to-p doping should show topological transport phenomena even at room temperature.read more
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Dynamics of all the Raman-active coherent phonons in Sb2Te3 revealed via transient reflectivity
Katsura Norimatsu,Katsura Norimatsu,Masaki Hada,Masaki Hada,Shuhei Yamamoto,Takao Sasagawa,Masahiro Kitajima,Yosuke Kayanuma,Kazutaka G. Nakamura +8 more
TL;DR: In this paper, the phonon dynamics in Sb2Te3 were investigated using femtosecond time-resolved reflection measurements, where the amplitude of coherent phonons strongly depends on the polarization of the excitation pulse, which can be explained by the analysis based on the Raman tensors.
Posted Content
Field theoretic study of electron-electron interaction effects in Dirac liquids
TL;DR: In this paper, the authors present recent results, obtained during the period 2012-2017, related to interaction effects in condensed matter physics systems such as planar Dirac liquids, e.g., graphene and graphene-like systems, the surface states of some topological insulators and possibly half-filled fractional quantum Hall systems.
Journal ArticleDOI
Electronic Coupling between Graphene and Topological Insulator Induced Anomalous Magnetotransport Properties
Lei Zhang,Ben-Chuan Lin,Yanfei Wu,Han-Chun Wu,Tsung-Wei Huang,Ching-Ray Chang,Xiaoxing Ke,Mert Kurttepeli,Gustaaf Van Tendeloo,Jun Xu,Dapeng Yu,Dapeng Yu,Zhi-Min Liao +12 more
TL;DR: The anomalous magnetotransport properties of graphene-topological insulator Bi2Se3 heterojunctions, which are sensitive to the electronic coupling between graphene and the topological surface state, are reported.
Journal ArticleDOI
Bulk-free topological insulator Bi2Se3 nanoribbons with magnetotransport signatures of Dirac surface states.
Gunta Kunakova,Luca Galletti,Sophie Charpentier,Jana Andzane,Donats Erts,François Léonard,Catalin D. Spataru,Thilo Bauch,Floriana Lombardi +8 more
TL;DR: In this paper, the authors demonstrate that Bi2Se3 nanoribbons, grown by a simple catalyst-free physical-vapour deposition, have inherently low bulk carrier densities and can be further made bulk-free by thickness reduction, thus revealing the high mobility topological surface states.
Journal ArticleDOI
Semirelativity in semiconductors: a review.
TL;DR: It is indicated that in various situations it is considerably easier to observe semirelativistic effects in semiconductors than the relativist effects in vacuum, and the relativistic analogy holds for orbital and spin properties of electrons in the presence of an external magnetic field.
References
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Superconducting Proximity Effect and Majorana Fermions at the Surface of a Topological Insulator
Liang Fu,Charles L. Kane +1 more
TL;DR: It is shown that linear junctions between superconductors mediated by the topological insulator form a nonchiral one-dimensional wire for Majorana fermions, and that circuits formed from these junctions provide a method for creating, manipulating, and fusing Majorana bound states.