Closed-form analytical model for plasmonic metasurfaces consisting of graphene disks

Abstract

In this paper, a closed-form analytical model is proposed for the fundamental plasmon mode of a metasurface of graphene disks. First, we derive an equivalent admittance for the graphene metasurface at the normal incidence of a plane wave using the Rayleigh expansion. This admittance is then expressed as a series R-L-C circuit obtained by analyzing the integral equation that governs the surface current on the graphene disks. Finally, by using the equivalence substitution method, the equivalent circuit for this structure is fully analyzed. The accuracy of the model is verified by comparison with the results of full-wave simulations. Examples of applications are provided to predict tunable transmission resonances and design broadband absorbers, thus demonstrating their convenience for practical device design.