Magneto-plasmonic scattering by a disk-shaped particle made of an artificial dielectric

Abstract

The main features of artificial dielectrics are high anisotropy and controllable heterogeneity, as well as adjustable values of their synthesized material parameters. In this work, we numerically study the scattering features of a disk-shaped particle made of an artificial dielectric (finely stratified structure, FSS) that is composed of magnetic and semiconductor constituents influenced by an external static magnetic field. The tensor-valued permittivity and permeability of the FSS are derived involving the effective medium theory. Due to a specific composition of the FSS, the material properties of the disk simultaneously acquire electric and magnetic gyrotropy, which depends on the proportion of the semiconductor and magnetic components included in the FSS. It is supposed that the ferromagnetic and plasma resonances of the constitutive materials are closely spaced. In particular, we examine the electric and magnetic dipole contributions to the scattering and absorption cross-sections obtained in the framework of the multipole decomposition method while accounting for the polarizability and magnetization induced in the particle by the field of incoming radiation. By varying the proportion of components of the artificial dielectric, we demonstrate the magneto-plasmonic functionality of the particle. Our presentation generalizes and complements several known solutions obtained separately for either magnetic or dielectric anisotropic particles. This approach can be used to study magneto-optical effects in metamaterials and metasurfaces composed of an ensemble of gyroelectric and gyromagnetic particles that is important for both plasmonic and photonic applications.