Coupling single atoms to a nanophotonic whispering-gallery-mode resonator

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, thus leading to new paradigms for quantum optics. In this poster, we demonstrate our system 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. Single atoms are coupled to a nanophotonic whispering-gallery-mode resonator using two different methods: 1) an optical guiding technique that makes use of diffracted light from a nanophotonic waveguide to direct cold atoms to the evanescent region of the resonator, and 2) an optical conveyor-belt consisting of a moving optical lattice for controlled delivery of trapped atoms. We will also discuss prospects of cooling and loading cold atoms into a trap in the nearfield directly using a cavity pump field. Our demonstration paves the 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.