Twin Metamaterials: Inversion Symmetry, Reverse Magnetism, and Interface States

Abstract

Artificial magnetism can be realized with metamaterials in high frequencies, which are important for many applications. However, such metamaterials need to be constructed with metal or high-relative-permittivity dielectric and thus may exhibit absorption loss. Here, we theoretically propose and experimentally demonstrate a pair of magnetic metamaterials that have inversion symmetry and are generated from a parent photonic crystal with low-relative-permittivity dielectric (${\ensuremath{\epsilon}}_{r}<4$). Interestingly, one metamaterial is paramagnetic, the other is diamagnetic, and the product of their effective relative permeabilities is close to 1 (${\ensuremath{\mu}}_{e1}>1$, ${\ensuremath{\mu}}_{e2}<1$, ${\ensuremath{\mu}}_{e1}{\ensuremath{\mu}}_{e2}\ensuremath{\approx}1$) in a broad frequency range. As a result, fascinating effects, such as wide-angle and wide-frequency near-perfect transmission and interface states, are observed in the systems.