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Updated: Jul 6, 2025

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Signatures of Prethermalization in a Quenched Cavity-Mediated Long-Range Interacting Fermi Gas
Zemao Wu1, Jijie Fan1, Xue Zhang1
1State Key Laboratory of Precision Spectroscopy, Institute of Quantum Science and Precision Measurement, East China Normal University, Shanghai 200062, China.
Abstract:
The coupling of ultracold quantum gases to an optical cavity provides an ideal system for studying the novel long-range interacting nonequilibrium dynamics. Here we report an experimental observation of the out-of-equilibrium dynamics of a degenerate Fermi gas in the cavity after quenching the pump strength over a superradiant quantum phase transition. The relaxation dynamics exhibits impressively different stages of a delay, violent relaxation, long-lifetime prethermalization, and slowly final thermalization due to the photon-mediated long-range interaction with dissipation. Importantly, we reveal that the lifetime of the system stayed on the prethermalization exhibits the superlinear scaling of the atom number. Furthermore, we show that the backaction of the superradiant cavity field on the gas causes the exchange of atoms between the normal and superradiant state in the early evolution and then induces the prethermalization. This work opens an avenue to explore complex nonequilibrium dynamics of the dissipatively long-range interacting Fermi gases.
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