Homogenization near resonances and artificial magnetism from dielectrics

The homogenization of periodic dielectric structures in harmonic regime usually leads to an effective permittivity tensor ɛ eff . It has been observed by Bouchitté and Felbacq [Waves Random Media 7 (1997) 245–256], that in the high contrast case (high conductivity fibers), this tensor depends on the angular frequency ω . In this Note, we enlight a new effect induced by microscopic resonances which leads in parallel to a possibly negative effective permeability μ eff ( ω ) (although the original medium is assumed to be nonmagnetic i.e. μ = 1 ).