A gauge theory for two-band model of Chern insulators and induced topological defects  

作　　者：Zhi-Wen Chang Wei-Chang Hao Xin Liu 

机构地区：[1]Institute of Theoretical Physics,Faculty of Sciences,Beijing University of Technology,Beijing 100124,China [2]School of Physics,Beihang University,Beijing 100191,China

出　　处：《Communications in Theoretical Physics》2022年第1期124-133,共10页理论物理通讯（英文版）

基　　金：The authors XL and ZC acknowledge the financial support from the Natural Science Foundation of Beijing Grant No.Z180007;the National Science Foundation of China Grant No.11572005;WH acknowledges the support from the National Science Foundation of China Grant No.11874003 and Grant No.51672018.

摘　　要：In this paper a gauge theory is proposed for the two-band model of Chern insulators.Based on the so-calle't Hooft monopole model,a U(1)Maxwell electromagnetic sub-field is constructed from an SU(2)gauge field,from which arise two types of topological defects,monopoles and e2 merons.We focus on the topological number in the Hall conductance σ_(xy)=e^(2)/hC,where C is the Chern number.It is discovered that in the monopole case C is indeterminate,while in the meron case C takes different values,due to a varying on-site energy m.As a typical example,we apply this method to the square lattice and compute the winding numbers(topological charges)of the defects;the C-evaluations we obtain reproduce the results of the usual literature.Furthermore,based on the gauge theory we propose a new model to obtain the high Chern numbers|C|=2,4.

关 键 词：Chern insulator Chern number MONOPOLE meron 

分 类 号：O469[理学—凝聚态物理]