Superradiant quantum beats driven by ground-state–Rydberg-state coherences

Quantum beats in superradiance arise from coherent interference between collective emission from independent transitions, fundamentally distinct from single-atom quantum beats. In this work, we report the observation of quantum beats generated from ground-state–Rydberg-state atomic coherences in a cold atomic ensemble. Using phase-matched emission, we observe various time-resolved and time-integrated beating patterns that depend on the storage time between excitation and readout pulses. We develop a detailed model of the readout and emission processes, which quantitatively reproduces all observed beating signatures.