Observation of Anomalous π Modes in Photonic Floquet Engineering.

Recent progress on Floquet topological phases has shed new light on time-dependant quantum systems, among which one-dimensional (1D) Floquet systems have been under extensive theoretical research. However, an unambiguous experimental observation of these 1D Floquet topological phases is still lacking. Here, by periodically bending an ultrathin metallic array of coupled corrugated waveguides, a photonic Floquet simulator was well designed and successfully fabricated to mimic the periodically driven Su-Schrieffer-Heeger model.