Superradiant-coupled trapped atomic ensemble on an integrated microring circuit

Integrating cold atoms with nanoscale photonic structures promises stronger atom-light interactions and potentially scalable quantum applications. However, it remains a challenging task to efficiently trap a large ensemble of cold atoms on an integrated nanophotonic circuit. In this poster, we demonstrate the first realization of efficient atom loading and trapping into an optical microtrap above a nanophotonic microring resonator. Utilizing degenerate Raman-sideband cooling with a built-in spin-motion coupling in the microtrap, nearly a hundred atoms are loaded into a small optical microtrap, achieving a trap lifetime approaching one second. The trapped atoms display large cooperative coupling and superradiant decay into the whispering-gallery mode of the microring resonator, holding promise for explorations of new collective effects on an integrated nanophotonic circuit. Our demonstration paves the way towards various applications in quantum nonlinear optics, quantum simulations, sensing, and quantum chemistry using cold atom-powered nanophotonic circuits.