Spatial-dispersion-induced birefringence in metamaterials with cubic symmetry

Abstract

We consider an array of isotropic particles possessing electric polarizability located in the sites of a cubic lattice. The dispersion properties of the structure and the polarization of eigenmodes are studied employing the discrete dipole model. We reveal the features beyond the effective medium model, namely, the anisotropy of the structure induced by spatial dispersion, and suggest a simple experiment allowing one to observe the effect. Additionally, we demonstrate that the eigenmodes of the structure are neither transverse nor longitudinal but have a ``mixed'' polarization state in the general case.