Topological Insulators at Room Temperature

Zhang, Haijun ; Liu, Chao-Xing ; Qi, Xiao-Liang ; Dai, Xi ; Fang, Zhong ; Zhang, Shou-Cheng

SLAC National Accelerator Laboratory

关键词: Electronic Structure;    Surface Properties;    Tellurium Alloys;    36 Materials Science;    Selenium Alloys;   

DOI  :  10.2172/974186
RP-ID  :  SLAC-PUB-13934
RP-ID  :  AC02-76SF00515
RP-ID  :  974186

美国|英语

来源: UNT Digital Library

【 摘 要 】

Topological insulators are new states of quantum matter with surface states protected by the time-reversal symmetry. In this work, we perform first-principle electronic structure calculations for Sb{sub 2}Te{sub 3}, Sb{sub 2}Se{sub 3}, Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} crystals. Our calculations predict that Sb{sub 2}Te{sub 3}, Bi{sub 2}T e{sub 3} and Bi{sub 2}Se{sub 3} are topological insulators, while Sb{sub 2}Se{sub 3} is not. In particular, Bi{sub 2}Se{sub 3} has a topologically non-trivial energy gap of 0.3eV , suitable for room temperature applications. We present a simple and unified continuum model which captures the salient topological features of this class of materials. These topological insulators have robust surface states consisting of a single Dirac cone at the {Lambda} point.