Negative-permeability electromagnetically induced transparent and magnetically active metamaterials

tions, but currently their performance is limited by the occurrence of losses—particularly radiation losses, which dominate over their dissipative counterparts even in the optical regime. Here, a metamaterial configuration is conceived that judiciously generalizes the traditional electromagnetically induced transparency EIT scheme—by which radiation losses can be restrained—in such a way that EIT can be observed and exploited in negative-magnetic metamaterials. Analytic theory and three-dimensional simulations unveil the required route: introduction of poor-conductor meta-atoms next to the good-conductor meta-atoms of a magnetic metamaterial. This setup results in a frequency band where the metamaterial remains negative-magnetic, while its loss-performance dramatically improves owing to suppression of radiation damping. Furthermore, we show that placing the two meta-atoms on orthogonal planes gives rise to a passive anisotropic metamaterial exhibiting permeabilities with negative real parts Re 0 and active imaginary parts Im 0 for an e +it time