Subradiance with Saturated Atoms: Population Enhancement of the Long-Lived States
A. Cipris, Noel Araujo Moreira, T. S. do Espirito Santo, P. Weiss, Celso J. Villas-Bôas, Robin Kaiser, William Guerin, Romain Bachelard
Abstract
Dipole-dipole interactions are at the origin of long-lived collective atomic states, often called subradiant, which are explored for their potential use in novel photonic devices or in quantum protocols. Here, we study subradiance beyond the single-excitation regime and experimentally demonstrate a 200-fold increase in the population of these modes, as the saturation parameter of the driving field is increased. We attribute this enhancement to a mechanism similar to optical pumping through the well-coupled superradiant states. The lifetimes are unaffected by the pump strength, as the system is ultimately driven toward the single-excitation sector. Our study is a new step in the exploration of the many-body dynamics of large open systems.