Plasmon modes in N-layer gapped graphene

We investigate plasmon dispersions and Landau damping in multi-layer gapped graphene structures consisting of N, up to 5, gapped graphene sheets grown on dielectric spacer within random-phase-approximation at zero temperature. First of all, the results show that one in-phase optical and N-1 out-of-phase acoustic plasmon modes are found in the system. In addition, the imbalance of carrier density and the separation between layers affect remarkably on plasmon characters, and plasmon frequencies increase pronouncedly with the increase in the number of layers in the structure. Especially, the increasing band gap leads to the significantly decreasing plasmon frequencies in large wave-vector region. Finally, the number of low carrier density graphene sheets is equal to the number of plasmon branches separated from the others whereas the order of these layers affects weakly on plasmon curves.