标题：Prediction of a large-gap quantum-spin-Hall insulator: Diamond-like GaBi bilayer
作者：Wang, Aizhu; Du, Aijun; Zhao, Mingwen
作者机构：[Wang Aizhu] School of Physics, Shandong University, State Key Laboratory of Crystal Materials, Jinan, Shandong 250100, China.;[Zhao Mingwen] School o 更多
通讯作者地址：[Du, AJ]Queensland Univ Technol, Sch Chem Phys & Mech Engn, Brisbane, Qld 4001, Australia.
关键词：topological insulators; first-principles calculations; two-dimensional; cubic-diamond-like lattice; Rashba spin splitting; band inversion
摘要：A quantum-spin-Hall (QSH) state was achieved experimentally, albeit at a low critical temperature because of the narrow band gap of the bulk material. Twodimensional topological insulators are critically important for realizing novel topological applications. Using density functional theory (DFT), we demonstrated that hydrogenated GaBi bilayers (HGaBi) form a stable topological insulator with a large nontrivial band gap of 0.320 eV, based on the state-of-the-art hybrid functional method, which is implementable for achieving QSH states at room temperature. The nontrivial topological property of the HGaBi lattice can also be confirmed from the appearance of gapless edge states in the nanoribbon structure. Our results provide a versatile platform for hosting nontrivial topological states usable for important nanoelectronic device applications.