Effective medium theory for anisotropic media with plasmonic core-shell nanoparticle inclusions

Abstract

Core-shell building blocks have been found useful in recent years as inclusions, in the search for metamaterials with tailored properties. Either the core or the shell of these composite inclusions may be metallic, and the dielectric component may be both radially anisotropic and radially inhomogeneous. In tunable anisotropic metamaterials, the tuning may then be achieved through the host, the core, or some combination thereof. However a theoretical picture is harder to build. Here we propose an approach to an effective medium theory for such materials, valid in the quasi-static limit. The method proceeds first by homogenising the interior of complex particle, and then uses standard anisotropic effective medium methods to provide bulk effective homogenized parameters. By varying the degree of inhomogeneity in the core, shell and dielectric-metal material volume fractions, the technique can be used as a tool for the design of metamaterials with specifically engineered properties. We find that metamaterial properties can be readily tuned by reorienting the optical axis of the host (e.g. liquid crystal). In particular, there is a possibility of switching between hyperbolic and conventional anisotropic metamaterial properties by
changing inclusion shell properties.

More information

Identifiers

ORCID for T.J. Sluckin: orcid.org/0000-0002-9163-0061

Catalogue record

Export record

Altmetrics