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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Widespread spin polarization effects in photoemission from topological insulators
Chris Jozwiak,Yulin Chen,Yulin Chen,Yulin Chen,Alexei V. Fedorov,James Analytis,James Analytis,Costel R. Rotundu,Andreas K. Schmid,Jonathan D. Denlinger,Yi-De Chuang,D.-H. Lee,D.-H. Lee,Ian R. Fisher,Ian R. Fisher,Robert J. Birgeneau,Robert J. Birgeneau,Zhi-Xun Shen,Zhi-Xun Shen,Zahid Hussain,Alessandra Lanzara,Alessandra Lanzara +21 more
TL;DR: In this article, high-resolution spin and angle-resolved photoemission spectroscopy (spin-ARPES) was performed on the three-dimensional topological insulator Bi2Se3 using a recently developed high-efficiency spectrometer.
Journal ArticleDOI
Topological Insulators from Group Cohomology
TL;DR: In this paper, the authors theoretically expand this classification, with the aim of topologically classifying band insulators, and they show that the proposed method can be applied to a wide class of crystals.
Journal ArticleDOI
Quantum anomalous Hall effect in time-reversal-symmetry breaking topological insulators
Cui-Zu Chang,Mingda Li +1 more
TL;DR: The quantum anomalous Hall effect (QAHE) as mentioned in this paper exhibits quantized Hall conductivity σ(yx) = e2/h without any external magnetic field and has been experimentally observed in thin films of the time-reversal symmetry breaking ferromagnetic (FM) topological insulators.
Journal ArticleDOI
Sn-doped Bi1.1Sb0.9Te2S bulk crystal topological insulator with excellent properties.
Satya Kushwaha,Ivo Pletikosic,Tian Liang,Andras Gyenis,Saul H. Lapidus,Yao Tian,He Zhao,Kenneth S. Burch,Jingjing Lin,Wudi Wang,Huiwen Ji,Alexei V. Fedorov,Ali Yazdani,Nai Phuan Ong,Tonica Valla,R. J. Cava +15 more
TL;DR: This work characterize Sn-BSTS via angle-resolved photoemission spectroscopy, scanning tunnelling microscopy, transport studies, X-ray diffraction and Raman scattering, presenting this material as a high-quality topological insulator that can be reliably grown as bulk single crystals and thus studied by many researchers interested in topological surface states.
Journal ArticleDOI
Lattice dynamics in Bi 2 Te 3 and Sb 2 Te 3 : Te and Sb density of phonon states
Dimitrios Bessas,Dimitrios Bessas,Ilya Sergueev,Ilya Sergueev,Hans-Christian Wille,D. Ebling,Raphaël P. Hermann,Raphaël P. Hermann +7 more
TL;DR: In this paper, the lattice dynamics in Bi and Sb were investigated both microscopically and macroscopically using x-ray diffraction, and heat capacity measurements, and a significant softening was observed for the density of vibrational states of Bi with respect to Sb, consistently with the mass homology relation in the longwavelength limit.
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.