Micro-structured Rydberg-interacting atoms coupled to a running-wave cavity – MIRIARC

High-numerical-aperture optics have started a new era for the field of cold atoms by enabling high-resolution imaging and control, towards applications in quantum simulations and quantum computing, up to manipulation of single-atom arrays. Controlled Rydberg-mediated atom-atom interactions established them as leading platforms for quantum information processing. Their performance scales with the number of individually addressed atoms, currently of a few thousands, close to ultimate constraints set by optics and geometry.
Optically connecting atomic arrays could lift this roadblock. For this, a currently missing piece of technology is an efficient and Rydberg-compatible system for entangling neutral atoms with optical photons. Indeed, strong atom-photon coupling usually relies on high-finesse optical cavities or nanophotonic structures, which both pose significant challenges in terms of optical losses and coupling stability, exacerbated by the sensitivity of Rydberg atoms to the presence of nearby surfaces.
We propose an experimental project based on a new paradigm, combining high-numerical-aperture optics with a centimeter-scale running-wave medium-finesse cavity. After demonstrating our ability to trap single Rydberg atoms in the cavity, we will focus on the yet unexplored physics of interactions between the running-wave cavity and atomic ensembles structured at the scale of a wavelength. Then, we will aim at accelerating atomic-state detection by three orders of magnitude. With our innovative setup, we will implement a deterministic single-photon source with a targeted efficiency above 90%. This highly efficient photon generation will allow us to reach our main and final objective of efficient atom-photon entanglement, a building block for future interconnections between atomic processors.
Reaching these objectives will extend the perspectives of both industrial atomic quantum processors and experimental physics of light-matter interactions. Beyond the scope of the project, our experimental system will open new avenues for quantum optics and for atomic physics combining short- and long-range interactions.