Observation of Time-Reversal-Protected Single-Dirac-Cone Topological-Insulator States in Bi₂Te₃ and Sb₂Te₃

Abstract

We show that the strongly spin-orbit coupled materials Bi2Te3 and Sb2Te3 and their derivatives belong to the Z2 topological-insulator class. Using a combination of first-principles theoretical calculations and photoemission spectroscopy, we directly show that Bi2Te3 is a large spin-orbit-induced indirect bulk band gap (δ~150meV) semiconductor whose surface is characterized by a single topological spin-Dirac cone. The electronic structure of self-doped Sb2Te3 exhibits similar Z2 topological properties. We demonstrate that the dynamics of spin-Dirac fermions can be controlled through systematic Mn doping, making these materials classes potentially suitable for topological device applications.

Department(s)

Physics

Keywords and Phrases

Band Gaps; Device Application; Dirac Fermions; First-principles; Large Spin; Materials Class; Mn-doping; Photoemission Spectroscopy; Self-doped; Spin Orbits; Theoretical Calculations; Time-reversal; Topological Properties; Doping (Additives); Electronic Structure; Emission Spectroscopy; Manganese; Manganese Compounds; Sound Reproduction; Spin Dynamics

International Standard Serial Number (ISSN)

0031-9007

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2009 American Physical Society (APS), All rights reserved.

Publication Date

01 Sep 2009

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