Demonstration of atom-light interaction on a nanophotonic microring circuit

Interfacing cold atoms with nanoscale photonic structures promises stronger atom-light interactions and novel quantum functionalities via dispersion engineering, controlled photon propagation, topology, and chiral quantum transport. Our approach is based on high quality silicon nitride microring resonators fabricated on a transparent membrane substrate, which is compatible with laser cooling and trapping of cold atoms. This platform holds great promises as a scalable on-chip atom cavity QED system with strong and cooperative atom-light coupling. In this poster, we demonstrate an efficient optical guiding technique for trapping cold atoms in the near field of a planar nanophotonic circuit, realize atom-photon coupling to a whispering-gallery mode in a microring resonator. From the observation of the atom-induced transparency for light coupled to a microring, we characterize the atom-photon coupling rate, extract guided atom flux, and further explore the possibility of trapping single guided atoms directly on the microring waveguide. Our demonstration paves a way to explore collective quantum optics and many-body physics by forming an organized atom–nanophotonic hybrid lattice and inducing tunable long-range atom-atom interactions with photons on a nanophotonic circuit.