Magic in twisted transition metal dichalcogenide bilayers
Name
s41467-021-27042-9.pdf
Description
Published version
Size
1.55 MB
Format
Unknown
Checksum (MD5)
c86cb422c556dc975cfe1afdd179c49e
Author(s)
Devakul, Trithep
Crépel, Valentin
Zhang, Yang
Fu, Liang
Date Issued
December 2021
Journal
Nature Communications
Publisher
Springer Science and Business Media LLC
Citation
Devakul, Trithep, Crépel, Valentin, Zhang, Yang and Fu, Liang. 2021. "Magic in twisted transition metal dichalcogenide bilayers." Nature Communications, 12 (1).
Version
Final published version
Abstract
The long-wavelength moiré superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moiré bands in twisted transition metal dichalcogenide homobilayers, focusing on WSe2, at small twist angles using a combination of first principles density functional theory, continuum modeling, and Hartree-Fock approximation. We reveal the rich physics at small twist angles θ < 4∘, and identify a particular magic angle at which the top valence moiré band achieves almost perfect flatness. In the vicinity of this magic angle, we predict the realization of a generalized Kane-Mele model with a topological flat band, interaction-driven Haldane insulator, and Mott insulators at the filling of one hole per moiré unit cell. The combination of flat dispersion and uniformity of Berry curvature near the magic angle holds promise for realizing fractional quantum anomalous Hall effect at fractional filling. We also identify twist angles favorable for quantum spin Hall insulators and interaction-induced quantum anomalous Hall insulators at other integer fillings.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/s41467-021-27042-9
