First and second sound in a highly elongated Fermi gas at unitarity

Abstract

We consider a Fermi gas at unitarity trapped by a highly elongated harmonic potential and solve the equations of two fluid hydrodynamics at finite temperature. The propagation of sound waves as well as the discretized solutions in the presence of weak axial trapping are considered. The relevant thermodynamic functions entering the hydrodynamic equations are discussed in the superfluid and normal regimes in terms of universal scaling functions. Both first sound and second sound solutions are calculated as a function of temperature and the role of the superfluid density is explicitly pointed out. The density fluctuations in the second sound wave are found to be large enough to be measured as a consequence of the finite thermal expansion coefficient of the gas. Emphasis is given to the comparison with recent experimental data.

15 pages, 11 figures

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Cited by in corpus (20)

• A Mixture of Bose and Fermi Superfluids
• Connecting strongly correlated superfluids by a quantum point contact
• Superfluid filaments of dipolar bosons in free space
• Tunneling transport of unitary fermions across the superfluid transition
• Breakdown of the Wiedemann-Franz law in a unitary Fermi gas
• Collective oscillations of a trapped quantum gas in low dimensions
• Superfluid signatures in a dissipative quantum point contact
• Discontinuities in the First and Second Sound Velocities at the Berezinskii-Kosterlitz-Thouless Transition
• Counter-flow instability of a quantum mixture of two superfluids
• Second sound in 2D Bose gas: from the weakly interacting to the strongly interacting regime
• Hydrodynamic VS collisionless dynamics of a 1D harmonically trapped Bose gas
• Interaction-Assisted Reversal of Thermopower with Ultracold Atoms
• Hybridization of first and second sound in a weakly-interacting Bose gas
• Normal mass density of a superfluid Fermi gas at unitarity
• Second sound with ultracold atoms: A brief historical account
• Energy absorption spectroscopy of unitary Fermi gases in a uniform potential
• Two-fluid theory for superfluid system with anisotropic effective masses
• First and second sound in a two-dimensional dilute Bose gas across the Berezinskii-Kosterlitz-Thouless transition
• First and second sound of a unitary Fermi gas in highly elongated harmonic traps
• Hole-induced anomaly in the thermodynamic behavior of a one-dimensional Bose gas