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
Journal ArticleDOI
Single valley Dirac fermions in zero-gap HgTe quantum wells
B. Büttner,Chao-Xing Liu,Grigory Tkachov,E. G. Novik,C. Brüne,Hartmut Buhmann,Ewelina M. Hankiewicz,Patrik Recher,Björn Trauzettel,Shou-Cheng Zhang,Laurens W. Molenkamp +10 more
TL;DR: In this paper, the cone-like nature of the points in 2D HgTe quantum wells, where conduction and valance bands meet, has been investigated and shown to have similar properties to the spin-and valley-degeneracy of graphene.
Journal ArticleDOI
Emergent quantum confinement at topological insulator surfaces
Mohammad Saeed Bahramy,Phil D. C. King,A. de la Torre,Johan Juul Chang,Ming Shi,L. Patthey,Geetha Balakrishnan,Ph. Hofmann,Ryotaro Arita,Naoto Nagaosa,Felix Baumberger +10 more
TL;DR: In this article, a conceptually simple model, implementing a semiconductor-like band bending in a parameter-free tight-binding supercell calculation, can quantitatively explain the entire measured hierarchy of electronic states.
Journal ArticleDOI
Measurement of Intrinsic Dirac Fermion Cooling on the Surface of the Topological Insulator Bi 2 Se 3 Using Time-Resolved and Angle-Resolved Photoemission Spectroscopy
Yihua Wang,Yihua Wang,David Hsieh,Edbert J. Sie,Hadar Steinberg,Dillon Gardner,Young S. Lee,Pablo Jarillo-Herrero,Nuh Gedik +8 more
TL;DR: In this paper, the authors performed time and angle-resolved photoemission spectroscopy of a prototypical topological insulator (TI) Bi_2Se_3 to study the ultrafast dynamics of surface and bulk electrons after photoexcitation.
Journal ArticleDOI
A sudden collapse in the transport lifetime across the topological phase transition in (Bi 1-x In x ) 2 Se 3
Liang Wu,Matthew Brahlek,R. Valdés Aguilar,Andreas V. Stier,C. M. Morris,Yuval Lubashevsky,L. S. Bilbro,Namrata Bansal,S. Oh,N. P. Armitage +9 more
TL;DR: The quantum phase transition from a topological to a conventional insulator in In-doped Bi2Se3 is characterized by a sudden change in the transport lifetime, measured by means of optical spectroscopy as discussed by the authors.
Journal ArticleDOI
Epitaxial growth of topological insulator Bi2Se3 film on Si(111) with atomically sharp interface
Namrata Bansal,Yong Seung Kim,Eliav Edrey,Matthew Brahlek,Yoichi Horibe,K. Iida,Makoto Tanimura,Guohong Li,Tian Feng,Hang Dong Lee,Torgny Gustafsson,Eva Y. Andrei,Seongshik Oh +12 more
TL;DR: In this article, a two-phase growth process was proposed to achieve interfacial-layer-free epitaxial growth of Bi 2 Se 3 films on Si substrates, where a low temperature initial growth followed by a high temperature growth, second-phase-free atomically sharp interface was obtained between Bi 2 SE 3 and Si substrate, as verified by reflection high energy electron diffraction (RHEED), transmission electron microscopy (TEM) and X-ray diffraction.
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.