Cylinder- and Coated-cylinder-systems as Multifunctional Metamaterials: An Effective Medium Description

Abstract

Cylinder- and coated-cylinder-based metamaterials constitute one of the most appealing metamaterial categories, especially in high frequencies, i.e. THz to optical. The effective medium descriptions though employed for the analysis of such metamaterials show serious limitations, especially in the case of high-index dielectric cylinders or cylinders made of resonant materials, such as phonon-polariton or exciton-polariton materials. In this talk we will present an effective medium approach suitable for the analysis and description of cylinder-based metamaterials, of either simple or coated/multicoated cylinders. The approach is based on the well-known to the Solid State Physics community Coherent Potential Approximation (CPA) method, combined with a Transfer Matrix scheme for the case of multi-coated cylinders. We will demonstrate here the power of this approach in the case of polaritonic cylinder systems and in systems of graphene-made nanotubes. In both cases a rich metamaterial behavior has been observed, including frequency regions of engineerable negative permittivity, negative permeability, and in some cases negative refractive index and hyperbolic response.