Much as in the case of (topological) insulators, topology plays an important role in periodically driven systems. They lead to interesting edge phenomena and bulk-edge connections which are quite different from static systems. A periodic table for non-interacting systems can be derived in much the same way as for band insulators. Moreover, topologically protected drives can arise in interacting systems.
I will review some recent progress in the direction of establishing bulk edge connections and topological invariants for Floquet systems as well as in classifying local Unitary operators.
