Collective dynamics of an atomic ensemble coupled to a microring resonator

Integrating neutral atoms with nanophotonic structures enables engineered atom-light interactions, giving rise to rich quantum optics phenomena and new opportunities for quantum technologies. A key example is collective emission from densely packed atoms coupled to nanophotonic waveguides or resonators, where strong atom-atom interactions mediated by free-space radiation modes and the nanophotonic guided modes coexist and compete. In this work, we investigate how collective emission develops in the presence of a nanophotonic structure, using singly to nearly-fully excited ensemble of up to 70 atoms evanescently coupled to a nanophotonic microring resonator. We present the experimental platform and discuss representative observations such as superradiance and selective collective emission behaviors to free space and the microring, respectively.