Size-governed electromagnetic absorption by metal particles

Abstract
Electromagnetic absorption by submicrometer conductors is qualitatively different from Drude absorption by bulk metals. Measurements performed between radio and far-infrared frequencies with metals having diameters of about 20 nm are now analyzed with the Landau-Lifshitz-Looyenga effective-medium formula. This procedure showed that the experimental data are consistent with a size-induced metal-insulator transition. Microwave measurements rule out a significant magnetic-dipole contribution to the absorption by mesoscopic conductors.