Spin-dipole mode in a trapped Fermi gas near unitarity
Authors: Tajima H., Recati A., Ohashi Y.
Autors Affiliation: RIKEN, Quantum Hadron Phys Lab, Nishina Ctr RNC, Wako, Saitama 3510198, Japan; Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Italy; Univ Trento, Dipartimento Fis, I-38123 Povo, Italy; Ist Nazl Fis Nucl, Trento Inst Fundamental Phys & Applicat, I-38123 Trento, Italy; Keio Univ, Dept Phys, Kohoku Ku, Yokohama, Kanagawa 2238522, Japan
Abstract: We theoretically investigate the spin-dipole oscillation of a strongly interacting Fermi gas confined by a harmonic trapping potential. By using a diagrammatic strong-coupling theory combined with a local density approximation and a sum rule approach, we study the temperature dependence of the spin-dipole frequency near unitarity. The connection of the spin-dipole frequency with the spin susceptibility and the pairing correlations is exploited. While the spin-dipole frequency exactly coincides with the trap frequency in a noninteracting Fermi gas, it is shown to be strongly enhanced in the superfluid state, because of the suppression of the spin degree of freedom due to the spin-singlet Cooper-pair formation. In strongly interacting Fermi gases, such enhancement occurs even above the superfluid phase transition temperature, due to the strong pairing correlations.
Journal/Review: PHYSICAL REVIEW A
Volume: 101 (1) Pages from: 013610-1 to: 013610-7
KeyWords: THERMODYNAMICS; OSCILLATIONS; RESONANCES; BEHAVIORDOI: 10.1103/PhysRevA.101.013610Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-08-07References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here