Abstract
We investigate the effect of uniaxial heterostrain on the interacting phase diagram of magic-angle twisted bilayer graphene. Using both self-consistent Hartree-Fock and density-matrix renormalization group calculations, we find that small strain values () drive a zero-temperature phase transition between the symmetry-broken “Kramers intervalley-coherent” insulator and a nematic semimetal. The critical strain lies within the range of experimentally observed strain values, and we therefore predict that strain is at least partly responsible for the sample-dependent experimental observations.
- Received 11 January 2021
- Accepted 30 May 2021
DOI:https://doi.org/10.1103/PhysRevLett.127.027601
© 2021 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Stretching Solves a Mystery of Magic-Angle Graphene
Published 6 July 2021
Numerical simulations show that discrepancies between experiments on graphene bilayers can be attributed to tiny amounts of strain applied to the samples.
See more in Physics