Trapped modes and resonances in gyrotropic graphene stacks

This paper examines the anomalous electromagnetic wave interactions with gyrotropic graphene-dielectric stacks and characterizes their perturbed wave resonances. Expressions for the dispersion relations, trapped mode condition, and the propagating and evanescent modes in the gyrotropic graphene stack have been derived and numerically quantified. The evanescent modes supported in the ambient medium couple as propagating modes in the gyrotropic graphene-dielectric stack at the discrete frequencies of the trapped modes. Valuation of the resonances in the material tensor and the resonances around the trapped modes that result in transmission anomalies (total transmission and total reflection) and field amplifications in the gyrotropic graphene is described. The effects of the chemical potential and the external magnetic field on the number of discrete trapped modes and subsequently on the transmission resonances are numerically assessed.