Speaker
Description
We studied the localization properties of electrons in incommensurate twisted bilayer graphene, for twist angles encompassing the narrow-band regime, by numerically exact means.
Incommensurability effects were found to induce states with sub-ballistic properties in the narrow-band regime. These states are delocalized in momentum-space and follow non-Poissonian level statistics, in contrast with their ballistic counterparts found for close-by commensurate angles.
Transport results corroborate this picture: for large enough systems, the conductance decreases with system size for incommensurate angles within the sub-ballistic regime.
Our results are at odds with the current belief that, for small angles, there are no qualitative distinctions between commensurate and incommensurate structures. In particular, we show that incommensurability effects are of crucial importance in the narrow-band regime and that the incommensurate nature of a general twist angle must be taken into account for an accurate description of magic-angle twisted bilayer graphene.
