Magnetic response of parallel slabs metamaterials at THz frequencies

Abstract

Artificially engineered metamaterials consisting of nanocomposites (i.e. metal- dielectric) elements in the form of metallic split ring resonators (SRRs), parallel wires or slabs can provide unique optical responses at high frequencies that not available in naturally existing materials. A variety of metamaterials have been used in many important applications such as superlenses, tunable mirrors and negative index materials. Decreasing the size of the magnetic resonators is critical if strong magnetic response is desired at optical and near- infrared frequencies. However, this scaling breaks down at high frequencies causing saturation in the magnetic response. In this study, we present a transmission line theory with models the magnetic response of pair of metallic nanostripes separated by a dielectric material. The predicted by the model magnetic susceptibility χ𝑚 and magnetic resonance frequency (MRF) are compared to exact numerical simulations showing excellent agreement. Parametric study of the MRF dependence on the resonator’s sizes show a clear saturation for small resonators