Correlated insulating phases of twisted bilayer graphene at commensurate filling fractions: A Hartree-Fock study

Motivated by the recently observed insulating states in twisted bilayer graphene, we study the nature of the correlated insulating phases of the twisted bilayer graphene at commensurate filling fractions. We use the continuum model and project the Coulomb interaction onto the flat bands to study the...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. B 2020-07, Vol.102 (3), p.1, Article 035136
Main Authors: Zhang, Yi, Jiang, Kun, Wang, Ziqiang, Zhang, Fuchun
Format: Article
Language:English
Subjects:
Bilayers
Boron nitride
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
Continuum modeling
Correlation analysis
Electrons
Graphene
Ground state
Hartree approximation
Materials Science
Physics
Substrates
Symmetry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Motivated by the recently observed insulating states in twisted bilayer graphene, we study the nature of the correlated insulating phases of the twisted bilayer graphene at commensurate filling fractions. We use the continuum model and project the Coulomb interaction onto the flat bands to study the ground states by using a Hartree-Fock approximation. In the absence of the hexagonal boron nitride substrate, the ground states are the intervalley coherence states at charge neutrality (filling ν = 0 , or four electrons per moiré cell) and at ν = − 1 / 4 and − 1 / 2 (three and two electrons per cell, respectively) and the C2T symmetry-broken state at ν = − 3 / 4 (one electron per cell). The hexagonal boron nitride substrate drives the ground states at all ν into C2T symmetry broken-states. Our results provide good reference points for further study of the rich correlated physics in the twisted bilayer graphene.
ISSN:2469-9950
2469-9969
DOI:10.1103/PhysRevB.102.035136