Artificial magnetism and negative refractive index in three-dimensional metamaterials of spherical particles at near-infrared and visible frequencies

摘要

In this paper, we present a new class of 3D metamaterials that exhibit artificial magnetism and/or negative refractive index. These metamaterials consist of spherical particles made from strongly resonant materials such as ionic/semiconductor materials and noble metals. Their electromagnetic response is studied using the extended Maxwell-Garnett effective medium theory and an ab initio method based on multiple scattering theory. The agreement between both treatments is very good, rendering the effective medium approximation a useful guide for the experimentalist in the field.