Abnormal conductivity in low-angle twisted bilayer graphene.
Sci Adv
; 6(47)2020 Nov.
Article
em En
| MEDLINE
| ID: mdl-33219028
ABSTRACT
Controlling the interlayer twist angle offers a powerful means for tuning the electronic properties of two-dimensional (2D) van der Waals materials. Typically, the electrical conductivity would increase monotonically with decreasing twist angle owing to the enhanced coupling between adjacent layers. Here, we report a nonmonotonic angle-dependent vertical conductivity across the interface of bilayer graphene with low twist angles. More specifically, the vertical conductivity enhances gradually with decreasing twist angle up to a crossover angle at θc ≈ 5°, and then it drops notably upon further decrease in the twist angle. Revealed by density functional theory calculations and scanning tunneling microscopy, the abnormal behavior is attributed to the unusual reduction in average carrier density originating from local atomic reconstruction. The impact of atomic reconstruction on vertical conductivity is unique for low-angle twisted 2D van der Waals materials and provides a strategy for designing and optimizing their electronic performance.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China