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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The changing colors of a quantum-confined topological insulator.
Anthony Vargas,Susmita Basak,Fangze Liu,Baokai Wang,Eugen Panaitescu,Hsin Lin,Robert S. Markiewicz,Arun Bansil,Swastik Kar +8 more
TL;DR: This work reports on catalyst-free, high-quality single-crystalline Bi2Se3 with controlled lateral sizes and layer thicknesses that could be tailored down to a few nanometers and a few quintuple layers (QLs), respectively, and suggests that while purely 2D sheets of few QL-thick Bi2 Se3 do exhibit small band gaps, the presently observed large gaps can only result from a combined effect of confinement in all three directions.
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Determination of the energy band gap of Bi2Se3
Gerard Martinez,Benjamin A. Piot,M. Hakl,Marek Potemski,Yew San Hor,A. Materna,S. Strzelecka,A. Hruban,Ondřej Caha,Jiří Novák,Adam Dubroka,Cestmir Drasar,Milan Orlita,Milan Orlita +13 more
TL;DR: A combined magneto-transport, photoluminescence and infrared transmission study of Bi2Se3 unambiguously shows that the energy band gap of this material is direct and reaches Eg’s= (220 ± 5) meV at low temperatures.
Journal ArticleDOI
Fragility of surface states and robustness of topological order in Bi2Se3 against oxidation.
TL;DR: Topological surface states are protected against local perturbations, but this protection does not extend to chemical reaction over the whole surface, as demonstrated by theoretical studies of the oxidation of Bi(2)Se(3) and its effects on the surface spin polarization and current.
Journal Article
Predicting a new phase (T′′) of two-dimensional transition metal di-chalcogenides and strain-controlled topological phase transition
Fengxian Ma,Guoping Gao,Yalong Jiao,YuanTong Gu,Ante Bilic,Haijun Zhang,Zhongfang Chen,Aijun Du +7 more
TL;DR: In this article, a new phase of transition metal dichalcogenides (labeled as T′′), which is confirmed to be energetically, dynamically and kinetically stable by first-principles calculations was discovered.
Journal ArticleDOI
A high-sensitive and fast-fabricated glucose biosensor based on Prussian blue/topological insulator Bi2Se3 hybrid film.
TL;DR: The resulting biosensor was applied to detect the blood sugar in human serum samples without any pretreatment, and the results were comparatively in agreement with the clinical assay.
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.