Wavepacket dynamics in Floquet topological systems

Periodic driving, also known as Floquet engineering, is a powerful experimental technique to realize topological lattice models with ultracold atoms in optical lattices. Here, we report on the realization of distinct topological models using periodic driving with bosonic atoms in a hexagonal optical lattice. We probe different topological regimes using a combination of spectroscopic measurements and local Hall deflections, thereby revealing the topological invariants that characterize the different topological regimes. Depending on the modulation parameters, we show that genuine out-of-equilibrium Floquet topological systems can be realized without any static analogue. These systems are characterized by a generalized bulk-boundary correspondence, which can support topological edge modes even if the Chern numbers of all bulk bands vanish. We reveal this connection by preparing localized wavepackets at the edge of the systems, which directly signals the presence of topological edge modes.