Optically induced flat bands in twisted bilayer graphene

Abstract

Twisted bilayer graphene exhibits strong electronic correlations at the ``magic angle'' -- a special angle of the twist, at which isolated flat bands emerge in the material's band structure. The authors present here a new mechanism to induce isolated flat bands at angles below the magic angle using visible/infrared light. This mechanism enables optical control of the flatness, spectral isolation, and topological properties of the bands, using frequencies which are well below the material's bandwidth. Floquet engineering using optical fields and moir\'e superlattices may therefore play an important role in the exploration of on-demand nonequilibrium quantum phases of matter.

Topics & Concepts