Strain-Induced Quantum Phase Transitions in Magic-Angle Graphene

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 (epsilon similar to 0.1%-0.2%) 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.

Automated summary

Research on magic-angle twisted bilayer graphene reveals that small strain values can drive a zero-temperature phase transition between the symmetry-broken Kramers intervalley-coherent insulator and nematic semimetal. The critical strain falls within the experimentally observed range, suggesting that strain may partially account for sample-dependent experimental observations.