摘要
为了探究拓扑绝缘体中非拓扑缺陷对诱导零模态产生的影响,文中在粒子-空穴性对称的拓扑绝缘体中加入非拓扑缺陷(格点空位),经数值严格对角化,得出系统能级分布和粒子态密度分布,并利用陈数计算系统的全局相图。研究发现:非拓扑缺陷同样会诱导“规范不变”的零模态,并且具有非平庸的物理性质;当体系中存在奇数个格点空位时,总会有一个零能束缚态出现,而体系中存在偶数个格点空位时,局域束缚态具有有限能量;系统的粒子空穴对称性被破坏后,单格点空位诱导的零能态变为有限能量的束缚态;在无自旋霍尔丹模型中,诱导的零模态携带e/2分数电荷;在自旋的霍尔丹模型中,诱导的零模态携带1/2自旋磁矩。
To explore the influence of non topological defects of topological insulators on induced zero modes,in this paper,non topological defects(lattice vacancies)are added to topological insulators with particle hole symmetry.Numerically tightly diagonalized,the energy levels distribution and particle density of state distribution of the system are obtained,and the Chern number is used to calculate the global phase diagram of the system.It is found that it will also induce the“gauge invariant”zero modes,and has non trivial physical properties.If there are odd vacancies in the system,one zero mode always appears.While if even vacancies exist in the system,induced bound states have finite energy.When the particle hole symmetry is broken for the system,one lattice vacancy induced zero mode turns into a bound state with finite energy.In spinless Haldane model,the induced zero mode takes e/2 fractional charge;in spinful Haldane model,the induced zero mode takes 1/2 spin moment.
作者
屠威
吴亚杰
TU Wei;WU Yajie(School of Science,Xi’an Technological University,Xi’an 710021,China)
出处
《西安工业大学学报》
CAS
2022年第6期547-551,558,共6页
Journal of Xi’an Technological University
基金
陕西省自然科学基础研究计划项目(2021JM-421)。
关键词
拓扑绝缘体
粒子空穴对称性
格点空位
零模
topological insulators
particle hole symmetry
lattice vacancy
zero modes
