Tunable Non-Equilibrium Magic and Minimum Twist Angles in AA-Stacked Twisted Multilayer Graphene

Abstract: We report the discovery of a series of non-equilibrium magic angles at which isolated topological flat quasienergy bands form in AA-stacked twisted multilayer graphene under circularly polarized light. These non-equilibrium magic angles can be traced back to specific static twist angles where the bandwidth reaches a minimum \textit{without} the formation of isolated flat bands. We refer to these as minimum twist angles, in contrast to the magic angles observed in twisted bilayer graphene. We show that an applied displacement field can further flatten the optically induced topological flat bands accompanied by larger non-equilibrium magic angles. The discovery of these electrically tunable topological flat quasienergy bands is expected to open up a new avenue of exploring exotic Floquet-driven phenomena in AA-stacked twisted multilayer graphene.