A new and experimentally feasible observable for anomalous Floquet topology

In an international collaboration with Kyoto University, University of Hamburg and TU Berlin, we propose a new method to determine the presence of anomalous Floquet topology in periodically driven systems via a simple real-space bulk observable. Topology is an important concept in solid state physics and synthetic quantum systems connecting bulk topological indices to the presence of protected chiral states at the edge of the system. In periodically driven systems, however, these edge states can also exist for topologically trivial bands, a phenomenon known as anomalous Floquet topological insulators. While the identification of such phases usually requires the measurement of the edge states, we find that the dynamics of initially localized wave packets during the driving period also identifies the phase by tracing out a finite area. This constitutes a feasible proxy for anomalous topology that will help in studying these phases.
The preprint is available at Asteria et al.
