Observation of Collapse and Revival in a Superconducting Atomic Frequency Comb
Elena S. Redchenko, Matthias Zens, Martin Žemlička, Matilda Peruzzo, Farid Hassani, Riya Sett, P. Zieliński, Himadri Shekhar Dhar, Dmitry O. Krimer, Stefan Rotter, J. M. Fink · Physical Review Letters · 2025
Recent advancements in superconducting circuits have enabled the experimental study of collective behavior of precisely controlled intermediate-scale ensembles of qubits. In this work, we demonstrate an atomic frequency comb formed by individual artificial atoms strongly coupled to a single resonator mode. We observe periodic microwave pulses that originate from a single coherent excitation dynamically interacting with the multiqubit ensemble. We show that this revival dynamics emerges as a consequence of the constructive and periodic rephasing of the five superconducting qubits forming the vacuum Rabi split comb. In the future, similar devices could be used as a memory with in situ tunable storage time or as an on-chip periodic pulse generator with nonclassical photon statistics.