Floquet Ladder Lattice of Gain-Driven Polaritons

A Floquet ladder lattice (FLL) is created by introducing ultrastrong temporal modulation into a gain-embedded cavity magnonics platform. In contrast to conventional atomic lattices, the FLL is a synthetic polariton lattice manifested in the frequency dimension, embodying light-matter interaction, temporal diffraction, and gain-driven nonequilibrium dynamics. Distinct lattice phenomena-including bistability-enabled exfoliation, edge singularities, compact edge localization, and Floquet band gaps-are experimentally observed and theoretically analyzed. Benefiting from its highly flexible lattice architecture, the FLL enables a superior microwave frequency comb with on-demand engineering capabilities.