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

Abstract

The Lorenz-Mie formulation of electromagnetic scattering by a homogeneous, isotropic, dielectricmagnetic sphere was extended to incorporate topologically insulating surface states characterized by a surface admittance γ. 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 γ, when the sphere is either nondissipative or weakly dissipative. For large values of γ, 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 planewave propagation with positive or negative phase velocity.

Electromagnetic waves scattering from a sphere of complex conjugate medium

“…It is commonly used as a reference for any kind of electromagnetic scattering theory and applications. Complete analytical treatment of electromagnetic plane wave scattering by a homogeneous, isotropic, dielectric sphere can be traced back to an 1890 paper by Lorenz, though credit for that achievement is commonly given to 1908 paper by Mie [10] . In this study, the scattering of plane waves from CCM sphere is considered.…”

Nonreciprocal Dyakonov-wave propagation supported by topological insulators

“…The scalar amplitude coefficients A c1;c2 and A s1;s2 introduced in Eqs. (5) and (8), respectively, are related by the following boundary conditions imposed at the interface z 0. Two cases are considered: in case (i) the substrate possesses topologically insulating surface states characterized by the surface admittance γ [7], while in case (ii) the substrate possesses a surface charge characterized by the surface conductivityσ [22,24,25].…”

“…The discovery of topological insulators [1], such as the chalcogenides Bi 2 Se 3 , Bi 2 Te 3 , and Sb 2 Te 3 , has prompted a flurry of research activity, much of which has been directed toward revealing their optical properties [2][3][4]. To this end, the theory underpinning optical scattering from spheres made of topological insulators was recently developed [5]. Classically, a topological insulator may be modeled as an achiral biisotropic material whose nonreciprocity is captured by a magnetoelectric pseudoscalar γ [6].…”

Axion Mie theory of electron energy loss spectroscopy in topological insulators

“…As noted in Ref. [10], in this case the problem reduces to the one of light scattering by an optically active sphere, solved by Bohren long time ago [11,12]. A closely related problem arises also in the study of a so called chiral dielectric-magnetic medium [13].…”