Floquet Topological Phases in a Photonic Simple Lattice upon On‐Site Drives

Abstract

Floquet engineering provides an amazing way to reshape materials from topologically trivial to non‐trivial phases by exerting periodic drives. Among its vast investigations spanning various physical systems, the toolkit via driving on‐site potentials only is rarely employed. Here, a Floquet protocol that switches a simple lattice into a non‐trivial topological phase merely by driving its on‐site potentials is proposed. Non‐trivial topology arises from unpaired Floquet drives. Topological zero‐quasienergy states are found at boundaries between non‐trivial and trivial structures, being protected by sublattice symmetry. These states are experimentally demonstrated in a photonic platform. This approach can be extended to unveil more novel topological phenomena as well as to endow non‐trivial properties to a host of materials.