Topologically induced transparency in a two-phase metamaterial

It is theoretically and numerically demonstrated that a mixture of two topologically distinct material phases is characterized by an anomalous "transparency window" in a spectral range wherein the individual material phases are strongly reflecting. In particular, it is shown that a metamaterial formed by a metallic wire grid embedded in a magnetized plasma may support the propagation of waves with long wavelengths, notwithstanding the components, when taken separately, completely block the electromagnetic radiation. The effect is explained in terms of the topological properties of the magnetoplasmon. Furthermore, it is highlighted that some naturally available materials may be regarded as a mixture of two topologically distinct phases, and hence may be as well characterized by a similar anomalous transparency effect.