Topological flat bands and correlated states in twisted monolayer-bilayer graphene

Louk Rademaker, Ivan V. Protopopov, Dmitry A. Abanin

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Monolayer graphene placed with a twist on top of AB-stacked bilayer graphene hosts topological flat bands in a wide range of twist angles. The dispersion of these bands and gaps between them can be efficiently controlled by a perpendicular electric field, which induces topological transitions accompanied by changes of the Chern numbers. In the regime where the applied electric field induces gaps between the flat bands, we find a relatively uniform distribution of the Berry curvature. Consequently, interaction-induced valley- A nd/or spin-polarized states at integer filling factors are energetically favorable. In particular, we predict a quantum anomalous Hall state at filling factors ν=1,3 for a range of twist angles 1â<θ<1.4â. Furthermore, to characterize the response of the system to magnetic field, we computed the Hofstadter butterfly and the Wannier plot, which can be used to probe the dispersion and topology of the flat bands in this material.

Original languageEnglish (US)
Article number033150
JournalPhysical Review Research
Volume2
Issue number3
DOIs
StatePublished - Jul 2020
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy

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