Efficient fermi level modulation of coupled graphene-metal surface plasmon polaritons at GHz and low THz frequencies

In this paper we investigate how one can take add itional advantage of coupled metal-graphene plasmons. Hereto we derived the dispersion relation for coupled metal-graphene plasmons in multilayered structures. It is shown that an optimized multilayer structure, the solution of this dispersion relation of this structure is presented below. The coupled graphene-metal plasmon modes can depend very strongly on the electron concentration in the graphene layer. Various optimal structures with high tuneability will be presented for the GHz and THz frequencies, which eventually can be used in a wide range of applications.