Unusual magnetotransport in twisted bilayer graphene from strain-induced open Fermi surfaces.

ABSTRACT: Anisotropic hopping in a toy Hofstadter model was recently invoked to explain a rich and surprising Landau spectrum measured in twisted bilayer graphene away from the magic angle. Suspecting that such anisotropy could arise from unintended uniaxial strain, we extend the Bistritzer-MacDonald model to include uniaxial heterostrain and present a detailed analysis of its impact on band structure and magnetotransport. We find that such strain strongly influences band structure, shifting the three otherwise-degenerate van Hove points to different energies. Coupled to a Boltzmann magnetotransport calculation, this reproduces previously unexplained nonsaturating [Formula: see text] magnetoresistance over broad ranges of density near filling [Formula: see text] and predicts subtler features that ha

SUBMITTER: Wang X 

PROVIDER: S-EPMC10450440 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature