Data for: Selective Collective Emission from a Dense Atomic Ensemble Coupled to a Nanophotonic Resonator

<p>The data is for a paper (https://doi.org/10.1103/cdd5-r7h4) where we experimentally and theoretically study collective emission of a dense atomic ensemble coupled to a single mode in a nanophotonic microring resonator. Because many cold atoms are localized in a small volume, these trapped atoms collectively couple not only to the guided resonator mode but also to the non-guided modes in free space. Through tuning the atom-photon coupling and by adjusting the number of trapped atoms, we demonstrate superradiant emission to the microring resonator. For photon emission via the non-guided modes, our study reveals signatures of subradiance and superradiance when the system is driven to the steady state and to the timed-Dicke state, respectively. Our experimental platform thus presents the first atom-light interface with selective collective emission behavior into a guided mode and the environment, respectively. Our observation and methodology could shed light on future explorations of collective emission with densely packed quantum emitters coupled to nanophotonic light-matter interfaces.</p>