On the Dispersion Relation of Magnetoplasmons in a Planar Graphene-Based   Superlattice
  The dispersion relation for magnetoplasmons in a planar superlattice with periodically alternating regions of gapless and gapped modications of graphene has been derived within the frame of the random-phase approximation. The contribution of virtual transitions between the lower electron miniband and the upper hole miniband to the polarization operator has been taken into account in addition to the contribution of virtual intra-miniband transitions. 
P.V. Ratnikov
cond-mat.mes-hall