Breakdown of the Fermi polaron description near Fermi degeneracy at unitarity

Abstract

We theoretically investigate attractive Fermi polarons in three dimensions at finite temperature and impurity concentration through the many-body T-matrix theory and high-temperature virial expansion. By using the analytically continued impurity Green's function, we calculate the direct rf spectroscopy of attractive polarons in the unitary regime. Taking the peak value of the rf spectroscopy as the polaron energy and the full width half maximum as the polaron lifetime, we determine the temperature range of validity for the quasi-particle description of Fermi polarons in the unitary limit.

18 pages, 7 figures

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Cited by in corpus (22)

• Observation of a smooth polaron-molecule transition in a degenerate Fermi gas
• Quasiparticle lifetime of the repulsive Fermi polaron
• Theory of radio-frequency spectroscopy of impurities in quantum gases
• Heavy polarons in ultracold atomic Fermi superfluids at the BEC-BCS crossover: formalism and applications
• Exact quasiparticle properties of a heavy polaron in BCS Fermi superfluids
• High-precision numerical solution of the Fermi polaron problem and large-order behavior of its diagrammatic series
• Crossover polarons in a strongly interacting Fermi superfluid
• Fermi polarons at finite temperature: Spectral function and rf-spectroscopy
• Mesoscopic spin transport between strongly interacting Fermi gases
• Thermodynamic signatures of the polaron-molecule transition in a Fermi gas
• Radio-frequency response and contact of impurities in a quantum gas
• Multidimensional Spectroscopy of Time-Dependent Impurities in Ultracold Fermions
• Rabi oscillations and magnetization of a mobile spin-1/2 impurity in a Fermi sea
• Theory of the spectral function of Fermi polarons at finite temperature
• Raman spectroscopy of Fermi polarons
• Fermi spin polaron and dissipative Fermi-polaron Rabi dynamics
• Non-Hermitian Ferromagnetism in an Ultracold Fermi Gas
• Spectral function of Fermi polarons at finite temperature from a self-consistent many-body $T$-matrix approach in real frequency
• The Gor'kov and Melik-Barkhudarov correction to an imbalanced Fermi gas in the presence of impurities
• Microscopic many-body theory of two-dimensional coherent spectroscopy of excitons and trions in atomically thin transition metal dichalcogenides
• Repulsive Fermi and Bose Polarons in Quantum Gases
• The normal state of attractive Fermi gases from coupled-cluster theory