Tunable negative permeability in an isotropic dielectric composite

Abstract

A tunable isotropic negative effective permeability is experimentally demonstrated in a three-dimensional (3D) dielectric composite consisting of dielectric ceramic cube arrays by temperature changing. It shows that a strong subwavelength magnetic resonance can be excited in dielectric cubes corresponding to the first Mie resonance mode and can be continuously and reversibly adjusted from 13.65to19.28GHz with the temperature changing from −15to35°C. Accordingly, negative permeability can be performed in the frequency range of about 6GHz by adjusting the temperature. It provides a convenient route to design adaptive metamaterials and 3D invisible cloak.