Construction of a Molecular Cavity QED Platform for Quantum-Enhanced Sensing

        Quantum-enhanced sensing aims to surpass the Standard Quantum Limit (SQL) imposed by projection noise through engineered collective quantum correlations in many-body systems. Cavity Quantum Electrodynamics (cQED) experiments have enabled quantum-limited and non-destructive measurements in ultracold atomic systems, establishing the basis of powerful techniques for precision sensing. Extending these methods to molecules is highly motivated by their rich internal structure and enhanced sensitivity to external fields but remains experimentally challenging due to complex level structure.

        We are constructing a molecular cQED platform based on ultracold ensembles of SrF molecules. The apparatus integrates a cryogenic buffer-gas beam source that produces a cold and high-flux molecular beam, broadband optical slowing to compress the forward velocity distribution, and a magneto-optical trap with repumping to maintain optical cycling and prepare a trapped ensemble. To enable collective and minimally destructive readout, we engineer a high-finesse near-concentric optical cavity to provide strong collective coupling and favorable mode geometry for dispersive sensing protocols.

        We report on the current construction status and initial performance of key subsystems, including measurements of molecular flux, trapping performance, vacuum quality, and cavity properties. These establish progress toward a complete molecular cQED platform and lay the groundwork for future studies of cavity-based readout and quantum-enhanced sensing with molecules.