Selective collective emission from a dense atomic ensemble coupled to a nanophotonic resonator*

Collective atom-photon interaction has been actively explored in recent years. The ability to control and manipulate collective emission in atomic systems presents new opportunities for quantum many-body optics and quantum networks. In this talk, we investigate the signatures of selective collective emission from a dense atomic ensemble coupled to a nanophotonic resonator. We experimentally realize the trapping of dense atomic ensembles on an integrated nanophotonic microring resonator and study how these ensembles collectively couple to a resonator mode and other free pace modes. Specifically, we demonstrate superradiant emission in the resonator and reveal signatures of subradiant or superradiant emission into other free-space modes when the system is initially driven into a steady-state or a so-called timed-Dicke state, respectively. Our study sheds light on the realization of selective-radiance and enable new explorations of collective quantum optics with trapped atoms coupled to nanophotonic circuits.