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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Massive Dirac Fermion on the Surface of a Magnetically Doped Topological Insulator
Yulin Chen,Jiun-Haw Chu,James Analytis,Zhongkai Liu,Kyushiro Igarashi,Hsueh-Hui Kuo,Xiao-Liang Qi,Sung-Kwan Mo,Robert G. Moore,Donghui Lu,Makoto Hashimoto,Takao Sasagawa,Shou-Cheng Zhang,Ian R. Fisher,Zahid Hussain,Zhi-Xun Shen +15 more
TL;DR: This work introduced magnetic dopants into the three-dimensional topological insulator dibismuth triselenide to break the time reversal symmetry and further position the Fermi energy inside the gaps by simultaneous magnetic and charge doping, thus achieving an insulating gapped Dirac state.
Journal ArticleDOI
Low carrier concentration crystals of the topological insulator Bi$_{2-x}$Sb$_{x}$Te$_{3-y}$Se$_{y}$: a magnetotransport study
Yu Pan,D. Wu,J. R. Angevaare,H. Luigjes,Emmanouil Frantzeskakis,N. de Jong,E. van Heumen,T. V. Bay,B. Zwartsenberg,Y. K. Huang,M. Snelder,Alexander Brinkman,Mark S. Golden,A. de Visser +13 more
TL;DR: In this paper, the authors presented a study to further refine the bulk-insulating properties of the material system (Bi,Sb) with high resistivity and a low carrier concentration.
Journal ArticleDOI
Topological insulators in the quaternary chalcogenide compounds and ternary famatinite compounds
TL;DR: In this paper, first-principles calculations were presented to predict several 3D topological insulators in quaternary chalcogenide compounds of compositions I2-II-IV-VI4 and ternary famatinite compounds of composi- tions I3-V-VI 4.
Journal ArticleDOI
Spin and charge structure of the surface states in topological insulators
TL;DR: In this article, Zhang et al. investigated the spin and charge densities of surface states of the three-dimensional topological insulator Bi{}_{2}$Se${}_{3}$, starting from the continuum description of the material and showed that the position of the Dirac crossing in the spectrum of the surface states depends on the orientation of the interface.
Journal ArticleDOI
Tuning the vertical location of helical surface states in topological insulator heterostructures via dual-proximity effects.
Guangfen Wu,Guangfen Wu,Hua Chen,Hua Chen,Yan Sun,Xiaoguang Li,Xiaoguang Li,Xiaoguang Li,Ping Cui,Ping Cui,Cesare Franchini,Jinlan Wang,Xing-Qiu Chen,Zhenyu Zhang,Zhenyu Zhang,Zhenyu Zhang +15 more
TL;DR: First-principles approaches are used to establish accurate tunability of the vertical location of the TSS via intriguing dual-proximity effects, and lay the foundation for accurate manipulation of the real space properties of TSS in TI heterostructures of diverse technological significance.
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.