Topological photonics derived from dielectric materials

Abstract

Topological propagation of electromagnetic waves immune to scattering due to bend and defect is attracting significant interest. We have revealed recently that this amazing property can be realized in photonic crystals based on conventional dielectric materials, without application of external magnetic field and usage of special materials inherent in previous proposals. From the spatial symmetry of photonic crystals, an effective spin degree of freedom emerges in electromagnetic waves, which makes a topological state with time-reversal symmetry possible. Novel devices are expected via integration of topological photonics and electronics.