Topological Rashba-like edge states in large-gap quantum spin Hall insulators

作     者：Yuanjun Jin Li-Yong Gan Rui Wang Jinzhu Zhao Yueyue Shan Junfeng Liu Hu Xu 

作者机构：Department of Physics and Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China School of Materials Science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong Province South China University of Technology 510641 Guangzhou China Institute for Structure and Function and Department of Physics Chongqing University 400030 Chongqing China 

出 版 物：《Physical Review Materials》 (Physic. Rev. Mat.)

年 卷 期：2018年第2卷第11期

页      面：114207-114207页

核心收录：

基　　金：National Natural Science Foundation of China, NSFC, (11334003, 11404159, 11504303, 11674148) Science, Technology and Innovation Commission of Shenzhen Municipality National Science Fund for Distinguished Young Scholars, (2017B030306008) 

主　　题：Electronic structure First-principles calculations Rashba coupling Surface states Topological insulators 

摘      要：The search for large-band-gap quantum spin Hall (QSH) insulators, in which the dissipationless gapless edge states lie inside the bulk gap, is critical for their practical applications at room temperature. Based on first-principles calculations, we propose a sort of QSH insulator in a rectangular structure, i.e., AuSb, AuAs, and CuAs monolayers, which exhibits sizable bulk gaps up to 258 meV. These compounds host unexpected topological Rashba-like edge states, which exhibit strong dispersion with a nearly-free-electron feature. Such nontrivial edge states originate from spin-orbital coupling and an abrupt discontinuous potential across the surface. Furthermore, we argue that the AuSb monolayer can be epitaxially grown on a rutile TiO2(110) surface. Importantly, the thermodynamic stability of AuSb is enhanced while the topological features are perfectly preserved due to the weak van der Waals interaction at the interface. Our findings provide promising large-gap QSH candidates with exotic topological Rashba-like edge states that are in favor of experimental realization at room temperature.