Egocentric physics : just about Mie

Abstract

We show that the physics of anapole excitations can be accurately described in terms of a resonant state expansion formulation of standard Mie theory without recourse to Cartesian coordinate based `toroidal' currents that have previously been used to describe this phenomenon. In this purely Mie theory framework, the anapole behavior arises as a result of a Fano-type interference effect between different quasi-normal modes of the scatterer that effectively eliminate the scattered field in the associated multipole order.