物理学进展2023，Vol.43Issue(5)：151-160,10.DOI:10.13725/j.cnki.pip.2023.05.003
转角双层石墨烯中的势杂质效应
Potential Impurity Effect in Twisted Bilayer Graphene
摘要
Abstract
Flat band has attracted more and more interest in recent years,motivated by its discovery in twisted bilayer graphene(TBG).In this work,we report our study of the impurity effect on this flat band system,which is an important issue for real materials.Employing the Lanczos recursive method,we solve the local density of states(LDOS)around a potential impurity.We find for large impurity size,a series of bound states are formed inside the impurity,and the flat band peak in LDOS is suppressed near the impurity boundary and shifted by the impurity potential deep inside the impurity.As the impurity size becomes smaller,the effect on the flat band becomes weaker,as anticipated from the large scale of the underlying Wannier function.This property distinguishes with the usual flat band systems with small localized Wannier orbitals,and indicates the flat band in TBG is more stable against small-size impurities.关键词
杂质效应/转角双层石墨烯/局域态密度/平带Key words
impurity effect/twisted bilayer graphene/local density of states/flat band分类
物理学引用本文复制引用
刘泽众,王达..转角双层石墨烯中的势杂质效应[J].物理学进展,2023,43(5):151-160,10.基金项目
We thank R.-Y.Mao for his help on plotting fig-ures,and thank Q.-H.Wang,M.Yao,K.Xiang and Y.-Q.Liu for helpful discussions.This work is sup-ported by National Key R&D Program of China(Grant No.2022YFA1403201)and National Natural Science Foundation of China(Grant No.12274205 and No.11874205). （Grant No.2022YFA1403201）
