Topological Insulators at Room Temperature

Zhang, Haijun ; /Beijing, Inst. Phys. ; Liu, Chao-Xing ; /Tsinghua U., Beijing ; Qi, Xiao-Liang ; /Stanford U., Phys. Dept. ; Dai, Xi ; Fang, Zhong ; /Beijing, Inst. Phys. ; Zhang, Shou-Cheng ; /Stanford U., Phys. Dept.

关键词: ELECTRONIC STRUCTURE;    ENERGY GAP;    SURFACE PROPERTIES;    ANTIMONY ALLOYS;    TELLURIUM ALLOYS;    SELENIUM ALLOYS;    BISMUTH ALLOYS;    INTERMETALLIC COMPOUNDS Other;    MATSCI;   

DOI  :  10.2172/974186
RP-ID  :  SLAC-PUB-13934
PID  :  OSTI ID: 974186
Others  :  TRN: US201007%%687

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 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.