Square-octagon晶格中的量子自旋霍尔效应  

Quantum Spin Hall Effect on the Square-octagon Lattice

作　　者：王国祥 WANG Guoxiang(School of Science,Henan Institute of Technology,Xinxiang 453003,China)

机构地区：[1]河南工学院理学部,河南新乡453003

出　　处：《河南工学院学报》2022年第4期36-39,44,共5页Journal of Henan Institute of Technology

基　　金：河南工学院博士科研启动基金(KQ1814).

摘　　要：从晶格的紧束缚近似哈密顿量出发,计算square-octagon晶格纳米带的能带结构,分析其边界态特点,并通过Fukui-Hatsugai方法进一步验证系统的拓扑性。计算表明,在合适的参数下,Rahsba自旋轨道耦合作用能产生一对无能隙螺旋边界态,且该边界态受到时间反演对称性保护。同时,在半个布里渊区内的整数场之和为奇数,表明系统处于量子自旋霍尔态。Based on the tight-binding Hamiltonian,the band structure of the square-octagon lattice nanoribbon is calculated,and the characteristic of the edge states are analyzed.The topological properties of the systems are further determined by means of the Fukui-Hatsugai method.The results indicates that for proper parameters the Rashba spin-orbit coupling will generate a pair of gapless helical edge states,which are protected by the time-reversal symmetry invariant.Meanwhile,the sum of the integer field in half of the Brillouin zone is odd,suggesting the system is in a quantum spin Hall state.

关 键 词：square-octagon晶格 紧束缚模型 量子自旋霍尔效应 

分 类 号：O469[理学—凝聚态物理]