Chiral limit and origin of topological flat bands in twisted transition metal dichalcogenide homobilayers

Bibliographic Details
Title: Chiral limit and origin of topological flat bands in twisted transition metal dichalcogenide homobilayers
Authors: Valentin Crépel, Nicolas Regnault, Raquel Queiroz
Source: Communications Physics, Vol 7, Iss 1, Pp 1-6 (2024)
Publisher Information: Nature Portfolio, 2024.
Publication Year: 2024
Collection: LCC:Astrophysics
LCC:Physics
Subject Terms: Astrophysics, QB460-466, Physics, QC1-999
More Details: Abstract The observation of zero field fractional quantum Hall analogs in twisted transition metal dichalcogenides (TMDs) asks for a deeper understanding of what mechanisms lead to topological flat bands in two-dimensional heterostructures, and what makes TMDs an excellent platform for topologically ordered phases, surpassing twisted bilayer graphene. To this aim, we explore the chiral limits of massive Dirac theories applicable to C 3-symmetric moiré materials, and show their relevance for both bilayer graphene and TMD homobilayers. In the latter, the Berry curvature of valence bands leads to relativistic corrections of the moiré potential that promote band flattening, and permit a limit with exactly flat bands with nonzero Chern number. The relativistic corrections enter as a layer-orbit coupling, analogous to spin-orbit coupling for relativistic Dirac fermions, which we show is non-negligible on the moiré scale. The Berry curvature of the TMD monolayers therefore plays an essential role in the flattening of moiré Chern bands in these heterostructures.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2399-3650
Relation: https://doaj.org/toc/2399-3650
DOI: 10.1038/s42005-024-01641-6
Access URL: https://doaj.org/article/a3f18792c06040cc8e61c7eb3ef11843
Accession Number: edsdoj.3f18792c06040cc8e61c7eb3ef11843
Database: Directory of Open Access Journals
More Details
ISSN:23993650
DOI:10.1038/s42005-024-01641-6
Published in:Communications Physics
Language:English