Quasienergy spectrum of electrons in ac-driven graphene superlattice

Quasienergy spectrum of electrons in graphene superlattice subjected to the ac electric field was investigated. The ac-field vector was assumed to oscillate perpendicularly to the superlattice axis. Miniband width was found to change with ac-field amplitude changing. Such effect is due to the nonadditivity of the electron spectrum of graphene superlattice.