Curved-space topological phases in photonic lattices

We introduce topological phases in curved-space photonic lattices. In such systems, the interplay between the curvature of space and the topology of the system, as manifested in the topology of the band structure, gives rise to a wealth of new phenomena. We demonstrate the topological curved-space concepts in an experimentally realizable setting of a waveguiding layer covering the surface of a three-dimensional body, and show that the curvature of space can induce topological edge states, topological phase transitions, Thouless pumping, and localization effects. We also describe the analogy between our system and topological phases in dynamical curved space-time settings known from general relativity.