Cut-wire pairs and plate pairs as magnetic atoms for optical   metamaterials
  We study the optical properties of metamaterials made from cut-wire pairs or plate pairs. We obtain a more pronounced optical response for arrays of plate pairs -- a geometry which also eliminates the undesired polarization anisotropy of the cut-wire pairs. The measured optical spectra agree with simulations, revealing negative magnetic permeability in the range of telecommunications wavelengths. Thus, nanoscopic plate pairs might serve as an alternative to the established split-ring resonator design. 
G. Dolling, C. Enkrich, M. Wegener, J. Zhou, C.M. Soukoulis, S. Linden