Artificial permeability and antibonding magnetic resonance in a copper-structured metamaterial with symmetry-broken ring-plate resonators

Metallic metamaterials with magnetic resonance have attracted a lot of interest during the passed decades due to their potential applications on realizing artificial magnetism from zero frequency to optical spectrum. Since nonmagnetic natural materials, such as Cu, are lack of magnetic response at microwave frequencies, magnetic metamaterials usually contain a resonant structure to provide artificial permeability. As for the resonator, various structures such as split ring and cut-wire pair, were proposed to explore the resonant magnetic properties with paramagnetic or diamagnetic response in similar to natural magnetic materials. In previous work we calculated the transmission spectra and effective permeability of a double square ring of Cu and observed the antibonding magnetic response (i.e., a pair of antiparallel magnetic dipolar moments for each double-ring unit cell). Such an antibonding magnetic resonance is interesting not only for its transient magnetic moments distribution just like an oscillation version of the static antiferromagnetism, but also for its Fano-type resonance. In this paper, we simplify the double-ring to a ring-plate structure, and investigate the modified artificial permeability for this antibonding magnetic resonance by introducing asymmetric geometry.