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Effects of pressure and heterostrain on electronic bands of twisted bilayer graphene.

Effects of pressure and heterostrain on electronic bands of twisted bilayer graphene.

Authors :
Xiong, Wen
Wen, Lu
Lv, Xinyu
Li, Zhiqiang
Source :
Physics Letters A. Sep2023, Vol. 483, pN.PAG-N.PAG. 1p.
Publication Year :
2023

Abstract

We study the effects of pressure and uniaxial heterostrain on the energy bands and density of states in twisted bilayer graphene based on the effective continuum model. We find that extremely flat bands (one tenth of the bandwidth at magic angle 1.05°) can be achieved under pressure for a wide range of twist angles due to the enhancement of interlayer coupling strength. Under strain, pressure dramatically reduces the separation and widths of the flatband van Hove singularities at angles beyond the magic angle. Strain direction provides an addition parameter for tuning the flat bands to realize narrow bandwidth. Moreover, high-order van Hove singularities favoring strong electron correlations can be managed by applying pressure and strain. These effects may promote correlated electron phenomena at a broad range of twist angles. • The extremely narrow flat bands are achieved under pressure for a wide range of twist angles. • Pressure could be a factor that reverses partial effects of strain on twisted bilayer graphene system. • The evolutions of the van Hove singularities in density of states under both pressure and strain are presented. • High-order van Hove singularities are managed by applying pressure and strain. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03759601
Volume :
483
Database :
Academic Search Index
Journal :
Physics Letters A
Publication Type :
Academic Journal
Accession number :
170903382
Full Text :
https://doi.org/10.1016/j.physleta.2023.129048