Electromagnetic scattering by homogeneous, isotropic, dielectric-magnetic sphere with topologically insulating surface states

摘要

The Lorenz-Mie formulation of electromagnetic scattering by a homogeneous, isotropic, dielectric-magnetic sphere was extended to incorporate topologically insulating surface states characterized by a surface admittance gamma. Closed-form expressions were derived for the expansion coefficients of the scattered field phasors in terms of those of the incident field phasors. These expansion coefficients were used to obtain analytical expressions for the total scattering, extinction, forward scattering, and backscattering efficiencies of the sphere. Resonances exist for relatively low values of gamma, when the sphere is either nondissipative or weakly dissipative. For large values of gamma, the scattering characteristics are close to that of a perfect electrically conducting sphere, regardless of whether the sphere is composed of a dissipative or nondissipative material and regardless of whether that material supports plane-wave propagation with positive or negative phase velocity. (C) 2016 Optical Society of America