Interfacing single mm-wave and optical photons using Rydberg atoms: Part I

Optical light naturally interfaces with large ensembles of cold atoms, while GHz frequencies realize extremely strong light-matter coupling in synthetic platforms. In this talk, I will describe a hybrid quantum system for entangling and interconverting single optical and millimeter wave photons using ultracold Rydberg atoms. We employ cavity Rydberg EIT to map an optical photon onto a collective atomic Rydberg excitation, where the large electric dipole moment provides a strong nonlinear coupling to the mm-wave field. Our hybrid device consists of a crossed superconducting mm-wave cavity at 5K with a Q of 200,000 and an optical Fabry-Perot resonator, allowing optical access to couple to atoms. I will describe our experiment including the hybrid cavity design, cooling and manipulation of atoms in a cryogenic environment, techniques to stabilize high-finesse optical cavities against the vibrations from a cryocooler, and methods for generating dual-frequency photon interactions. The talk will be presented in two parts.