Effects of strain on the flat band in twisted bilayer graphene  

作　　者：张镇 文露 乔友凯 李志强 Zhen Zhang;Lu Wen;Youkai Qiao;Zhiqiang Li(College of Physics,Sichuan University,Chengdu 610064,China)

机构地区：[1]College of Physics,Sichuan University,Chengdu 610064,China

出　　处：《Chinese Physics B》2023年第10期585-591,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 11874271)。

摘　　要：Based on the effective continuum model, we systematically study the electronic band structures and density of states of twisted bilayer graphene near the magic angle under the influence of different types of strain, including shear strain,volume-preserving strain and biaxial strain. We find that the flat bands behave very differently under various types of strain.Volume-preserving strain generically leads to broader van Hove singularities associated with the flat bands compared with those under shear strain, with dissimilar strain direction dependence. The band structures and density of states under shear and volume-preserving strains change with the strain direction, while those under biaxial strain are independent of the direction of strain. In particular, the effect of biaxial strain on twisted bilayer graphene is geometrically and electronically similar to the influence of the twisted angle. Our results reveal the characteristic structures in the band structures and density of states under various types of strain, which can serve as fingerprints for exploring the effects of strain on the novel physics of this system.

关 键 词：GRAPHENE moirésuperlattice magic angle and strain 

分 类 号：O469[理学—凝聚态物理] TQ127.11[理学—电子物理学]