Non-hermitian topological photonics

The recent development of topological insulator states for photons has led to an exciting new field of “topological photonics,” which has as a central goal the development of extremely robust photonic devices. Topological insulator physics has been studied extensively in condensed matter and cold atoms. However, photonic systems offer the possibility of non-Hermitian effects through the engineering of optical gain and loss, which opens an entire new field of physics. In this talk, we will discuss our recent experimental work on non-Hermitian topological phenomena in coupled lattice systems, in particular the first demonstration of non-hermitian PT-symmetric topological interface state.