Onset of Floquet thermalization

Interacting many-body quantum systems are believed to heat up unboundedly under a periodic drive as there is no local conservation law to prevent this from happening. Here, the authors show that this belief may not be generally true. Their results indicate that under strong periodic driving quantum interference may suppress the heating and may lead to a nonthermal state, remembering properties of the initial state until infinite time. This is accounted for by the emergence of an approximately conserved local quantity. The freezing is more pronounced for smaller drive frequencies, putting it beyond the scope of conventionally used high-frequency expansions.