Surface plasmons in metamaterial heterostructures

Abstract

The extensive research of layered materials has revealed that it is possible to obtain a new degree of freedom for tuning the dispersion properties. Based on this concept, researchers have investigated the hyperbolic metamaterials. Recently, several kinds of photonic crystals have been proposed as classical counterparts of the layered materials. However, observation of nanostructured metamaterials from the perspective of the metamaterial structural design properties has remained difficult until now. Thus, we consider the propagation of surface plasmon polaritons (SPPs) at the boundary of geometrically different metamaterials. Herein, we consider two-layered and multilayered composites. All the heterostructures under consideration are made of the alternating graphene and dielectric sheets. We analytically estimate dispersion properties, absorption and propagation lengths of SPPs. The variation of graphene dielectric functions is described by the Drude model. On top of all, we analytically identify the key factors influencing propagation length along with the absorption enhancement highly desirable in terahertz photoconductive antennas and consider analytical variations aiming to tune the dispersion relations.