We propose a spectroscopic probe of the breaking and localization of Cooper pairs in an atomic Fermi superfluid interacting with a Rydberg impurity. This is achieved by monitoring the formation of diatomic and triatomic ultralong-range molecular species in the superfluid across the Bardeen-Cooper-Schrieffer (BCS)–Bose-Einstein condensation (BEC) crossover. The triatomic Rydberg molecule in the BEC regime heralds the trapping of a tightly bound Cooper pair, reminiscent of pion capture in nuclear matter, while the breaking of a Cooper pair on the BCS side by a diatomic Rydberg molecule is evocative of binary-star tidal disruption by a black hole. Spectroscopy of the Fermi superfluid and Rydberg molecules allows for an estimation of the Cooper-pair size while the Rydberg molecule binding energies discern many-body pairing effects.

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• Cold and ultracold molecules
• Fermionic condensates
• Rydberg gases