Giant topological magnetoelectric and optical Hall effects for a topological insulator as a defect in photonic crystals

Abstract

A system with a topological insulator slab sandwiched by two one-dimensional photonic crystals as a defect is investigated. A giant topological magnetoelectric effect is proposed which is characterized by two resonant peaks with half-unit transmissions and rich polarization behaviors in the photonic band gap. We also predict a giant optical Hall effect in our system, in which the transverse shift of the transmitted light could be 1000 times larger than the wavelength. These effects are purely from the $\ensuremath{\Theta}$-domain walls at the topological insulator interfaces and could be observed easily.