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 (ϵ∼0.1−0.2%) drive a zero-temperature phase transition between the symmetry-broken Kramers intervalley-coherent insulator and a nematic semi-metal. 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.
@article{arxiv.2012.09885,
title = {Strain-induced quantum phase transitions in magic angle graphene},
author = {Daniel E. Parker and Tomohiro Soejima and Johannes Hauschild and Michael P. Zaletel and Nick Bultinck},
journal= {arXiv preprint arXiv:2012.09885},
year = {2021}
}