Realization of ensemble atom trapping and collective atom-photon coupling on a nanophotonic microring circuit

We discuss our recent experiment demonstrating superradiantly-coupled trapped atomic ensemble in an optical microtrap above a nanophotonic microring resonator. Here, efficient trap loading is achieved via a degenerate Raman-sideband cooling (dRSC) scheme using built-in spin-motion coupling in the microtrap and a single optical pumping beam sent from freespace. We show that these dRSC-cooled atoms display large cooperative coupling and enhanced superradiant decay into a whispering-gallery mode in the microring resonator.