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
Reads0
Chats0
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
Citations
More filters
Book ChapterDOI
Topological Band Theory and the ℤ2 Invariant
TL;DR: In this paper, a pedagogical introduction to the theory of topological insulators is given, and the role of topology in band theory is discussed in detail, including theories of the electric polarization in one dimension, the integer quantum Hall effect in two dimensions and Z 2 topologically insulators in two and three dimensions.
Journal ArticleDOI
High-Pressure Phase Transitions and Structures of Topological Insulator BiTel
Yuanzheng Chen,Xiaoxiang Xi,Wai-Leung Yim,Feng Peng,Yanchao Wang,Hui Wang,Yanming Ma,Guangtao Liu,Chenglin Sun,Chunli Ma,Zhiqiang Chen,Helmuth Berger +11 more
TL;DR: In this article, a joint theoretical and experimental study up to 30 GPa was conducted to uncover two orthorhombic high-pressure phases of Pnma and P4/nmm structures named phases II and III.
Journal ArticleDOI
Topological magnetic crystalline insulators and corepresentation theory
Rui-Xing Zhang,Chao-Xing Liu +1 more
TL;DR: In this paper, the authors present a general theory of topological magnetic crystalline insulators in different types of magnetic crystals based on the core presentation theory of magnetic lattice symmetry groups.
Journal ArticleDOI
Ambipolar Surface Conduction in Ternary Topological Insulator Bi_2(Te_{1-x}Se_x)_3 Nanoribbons
TL;DR: Gate voltage enables ambipolar modulation of resistance (or conductance) in samples with thicknesses around or larger than 100 nm, indicating significantly enhanced contribution in transport from the gapless surface states.
Journal ArticleDOI
Spin Berry phase in anisotropic topological insulators
TL;DR: In this paper, the existence of a spin Berry phase in the presence and absence (due to crystal anisotropy) of cylindrical symmetry, that is, regardless of fulfilling the spin-to-surface locking condition, was demonstrated.
References
More filters
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.