Influence of randomness on the effective dielectric function of metal-dielectric composites for metamaterial purposes

The effective dielectric function of metal-dielectric composites consisting of spherical particles randomly distributed in a matrix is numerically investigated. The study, based on the spectral density theory, shows that local field fluctuations may critically affect the composite performance for metamaterial applications. It appears that randomness significantly modifies the effective dielectric function of composites consisting of metal inclusions embedded in dielectric matrix. The effect is less remarkable for dielectric inclusions in a metal matrix.