Observation of magnetization waves in negative-index photonic metamaterials

By measuring and calculating oblique-incidence transmittance spectra of a negative-index photonic metamaterial layer, the authors infer the in-plane dispersion relation of the magnetization wave. From the geometry and the dispersion shape, the authors conclude that coupling is predominantly via magnetic dipoles for wave propagation along the magnetic-dipole direction. These magnetization waves are the classical analog of magnon excitations of quantum-mechanical spins. (c) 2006 American Institute of Physics.