▎ 摘 要
The current density induced along the axis of graphene superlattice in the presence of ac and dc electric fields has been calculated. The dc electric field vector is assumed to have both transverse and longitudinal components with respect to the superlattice axis. The constant component of the current density is shown to oscillate with a change in the ac field amplitude. The longitudinal current-voltage characteristic of graphene superlattice contains a portion with negative differential conductivity. The maximum of the longitudinal current-voltage characteristic shifts to larger values of the longitudinal component of dc field with an increase in the transverse component of electric field.