Decoherence and Momentum Relaxation in Fermi-Polaron Rabi Dynamics: A Kinetic Equation Approach

Year: 2024

Authors: Wasak T., Sighinolfi M., Lang J., Piazza F., Recati A.

Autors Affiliation: Nicolaus Copernicus Univ Torun, Inst Phys, Fac Phys Astron & Informat, Grudziadzka 5, PL-87100 Torun, Poland; Max Planck Inst Phys Komplexer Syst, Nothnitzer Str 38, D-01187 Dresden, Germany; Univ Trento, INO CNR BEC Ctr, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, I-38123 Trento, Italy; Univ Cologne, Inst Theoret Phys, Zulpicher Str 77, D-50937 Cologne, Germany; Univ Augsburg, Inst Phys, Ctr Elect Correlat & Magnetism, Theoret Phys 3, D-86135 Augsburg, Germany; INFN, Trento Inst Fundamental Phys & Applicat, I-38123 Trento, Italy.

Abstract: Despite the paradigmatic nature of the Fermi-polaron model, the theoretical description of its nonlinear dynamics poses challenges. Here, we apply a quantum kinetic theory of driven polarons to recent experiments with ultracold atoms, where Rabi oscillations between a Fermi-polaron state and a noninteracting level were reported. The resulting equations separate decoherence from momentum relaxation, with the corresponding rates showing a different dependence on microscopic scattering processes and quasiparticle properties. We describe both the polaron ground state and the excited repulsive-polaron state and we find a good quantitative agreement between our predictions and the available experimental data without any fitting parameter. Our approach not only takes into account collisional phenomena, but also it can be used to study the different roles played by decoherence and the collisional integral in the strongly interacting highly imbalanced mixture of Fermi gases.

Journal/Review: PHYSICAL REVIEW LETTERS

Volume: 132 (18)      Pages from: 183001-1  to: 183001-7

More Information: We thank Matteo Zaccanti and Francesco Scazza for providing us with the experimental data. Discussion with J. Levinsen are also acknowledged. Financial support from the Italian MIUR under the PRIN2017 project CEnTraL (Protocol No. 20172H2SC4), from the Provincia Autonoma di Trento and from Q@TN, the joint lab between University of Trento, FBK-Fondazione Bruno Kessler, INFN-National Institute for Nuclear Physics, and CNR-National Research Council is acknowledged. This research is part of the Project No. 2021/43/P/ST2/02911 cofunded by the National Science Centre and the European Union Framework Programme for Research and Innovation Horizon 2020 under the Marie Sklodowska- Curie Grant Agreement No. 945339.
KeyWords: Electron gas; Excited states; Fermions; Integral equations; Kinetic theory; Polarons; Quantum theory
DOI: 10.1103/PhysRevLett.132.183001


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