Floquet higher-order topological states induced by driving on-site potentials

The advent of higher-order topological insulators has significantly expanded the landscape of topological phases of matter, with this framework further enriched by periodic (Floquet) driving. In most existing platforms, the implementation of Floquet higher-order topological insulators relies heavily on engineered coupling designs. Here, we propose a model that realizes a Floquet higher-order topological phase solely by periodic on-site potential modulations, and put forward its implementation in a photonic lattice system. We demonstrate the emergence of Floquet topological corner states and characterize their topological properties. These corner states exhibit robust localization during evolution in the presence of spatiotemporal disorders. The dependence of their existence on driving parameters is also discussed. Our results establish a simple and experimentally feasible route for achieving Floquet higher-order topological states.