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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Synthesis and characterisation of nanomaterials of the topological crystalline insulator SnTe
TL;DR: In this paper, the experimental procedures to obtain high quality crystal boules of the topological crystalline insulators (TCI), from which nanowires and microcrystals can be produced by the vapour-liquid-solid (VLS) technique.
Journal ArticleDOI
Topological Insulators from Group Cohomology
TL;DR: In this paper, a theory of time-reversal-invariant topological insulators with nonsymmorphic spatial symmetries was proposed, and the cohomological classification results in an atypical bulk-boundary correspondence for the topological topology.
Journal ArticleDOI
Air-Stable Electron Depletion of Bi2Se3 Using Molybdenum Trioxide into the Topological Regime
Mark T. Edmonds,Jack Hellerstedt,Jack Hellerstedt,Anton Tadich,Alex Schenk,Kane M. O'Donnell,Jacob Tosado,Jacob Tosado,Nicholas P. Butch,Nicholas P. Butch,Paul Syers,Johnpierre Paglione,Michael S. Fuhrer,Michael S. Fuhrer +13 more
TL;DR: Efficient electron depletion of Bi2Se3 via vacuum deposition of molecular MoO3 is demonstrated, lowering the surface Fermi energy to within ∼100 meV of the Dirac point, well into the topological regime.
Posted Content
Discovery of several large families of Topological Insulator classes with backscattering-suppressed spin-polarized single-Dirac-cone on the surface
Su-Yang Xu,Lewis Wray,Yuqi Xia,R. Shankar,A. Petersen,Alexei V. Fedorov,Hsin Lin,Arun Bansil,Yew San Hor,D. Grauer,R. J. Cava,M. Z. Hasan +11 more
TL;DR: In this article, the authors present theoretical prediction and experimental discovery of several new topological insulator classes in AB2X4(124), A2B2X5(225), MN4X7(147), and A2X2X'(221) [A,B = Pb,Ge,Sb,Bi and M,N=Pb, Bi and X,X'=Chalcogen family].
Journal ArticleDOI
Composite Dirac Liquids: Parent States for Symmetric Surface Topological Order
TL;DR: In this paper, the authors introduce composite Dirac liquids, which can appear at a strongly interacting surface of a three-dimensional electronic topological insulator and exhibit a gap to all charge excitations but nevertheless feature a single massless Dirac cone built from emergent electrically neutral fermions.
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.