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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Weyl semimetal in a topological insulator multilayer.
TL;DR: In this paper, a simple realization of the 3D Weyl semimetal phase was proposed, utilizing a multilayer structure, composed of identical thin films of a magnetically doped 3D topological insulator, separated by ordinary-insulator spacer layers.
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Quantized Anomalous Hall Effect in Magnetic Topological Insulators
Rui Yu,Wei Zhang,Haijun Zhang,Haijun Zhang,Shou-Cheng Zhang,Shou-Cheng Zhang,Xi Dai,Zhong Fang +7 more
TL;DR: A realization of a quantum anomalous Hall system is proposed by magnetically doping thin films of three-dimensional topological insulators and calculating the effects of various dopants and film thicknesses, which are predicted to have long-range ferromagnetic order, potentially joining dilute magnetic semiconductors as candidates for spintronic applications.
Journal ArticleDOI
A tunable topological insulator in the spin helical Dirac transport regime
David Hsieh,Yuqi Xia,Dong Qian,Lewis Wray,Jan Hugo Dil,Jan Hugo Dil,Fabian Meier,Fabian Meier,Jürg Osterwalder,Luc Patthey,Joseph Checkelsky,Nai Phuan Ong,Alexei V. Fedorov,Hsin Lin,Arun Bansil,D. Grauer,Yew San Hor,Robert J. Cava,M. Z. Hasan +18 more
TL;DR: The results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry’s phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime.
Journal ArticleDOI
Topological insulators and superconductors: Tenfold way and dimensional hierarchy
TL;DR: In this paper, the authors constructed representatives of topological insulators and superconductors for all five classes and in arbitrary spatial dimension d, in terms of Dirac Hamiltonians.
Journal ArticleDOI
WannierTools: An open-source software package for novel topological materials
QuanSheng Wu,Shengnan Zhang,Hai-Feng Song,Matthias Troyer,Alexey A. Soluyanov,Alexey A. Soluyanov +5 more
TL;DR: This code works in the tight-binding framework, which can be generated by another software package Wannier90 Mostofi et al. (2008), and can help to classify the topological phase of a given materials by calculating the Wilson loop, and get the surface state spectrum.
References
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Journal ArticleDOI
Generalized Gradient Approximation Made Simple
TL;DR: A simple derivation of a simple GGA is presented, in which all parameters (other than those in LSD) are fundamental constants, and only general features of the detailed construction underlying the Perdew-Wang 1991 (PW91) GGA are invoked.
Journal ArticleDOI
The rise of graphene
TL;DR: Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena can now be mimicked and tested in table-top experiments.
Journal ArticleDOI
Quantum Spin Hall Insulator State in HgTe Quantum Wells
Markus König,Steffen Wiedmann,Steffen Wiedmann,Christoph Brüne,Christoph Brüne,Andreas Roth,Andreas Roth,Hartmut Buhmann,Hartmut Buhmann,Laurens W. Molenkamp,Laurens W. Molenkamp,Xiao-Liang Qi,Xiao-Liang Qi,Shou-Cheng Zhang,Shou-Cheng Zhang +14 more
TL;DR: The quantum phase transition at the critical thickness, d = 6.3 nanometers, was independently determined from the magnetic field–induced insulator-to-metal transition, providing experimental evidence of the quantum spin Hall effect.
Journal ArticleDOI
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.