Sound propagation in elongated superfluid fermion clouds

Abstract

We use hydrodynamic equations to study sound propagation in a superfluid Fermi gas inside a strongly elongated cigar-shaped trap, with main attention to the transition from the BCS to the unitary regime. We treat first the role of the radial density profile in the quasi-onedimensional limit and then evaluate numerically the effect of the axial confinement in a configuration in which a hole is present in the gas density at the center of the trap. We find that in a strongly elongated trap the speed of sound in both the BCS and the unitary regime differs by a factor sqrt{3/5} from that in a homogeneous three-dimensional superfluid. The predictions of the theory could be tested by measurements of sound-wave propagation in a set-up such as that exploited by M.R. Andrews et al. [Phys. Rev. Lett. 79, 553 (1997)] for an atomic Bose-Einstein condensate.

References in corpus (8)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
• Weakly bound dimers of fermionic atoms
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover
• Comparison between a diagrammatic theory for the BCS-BEC crossover and Quantum Monte Carlo results
• Transition to hydrodynamics in colliding fermion clouds

Cited by in corpus (15)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
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• Connecting dissipation and phase slips in a Josephson junction between fermionic superfluids
• Counter-flow instability of a quantum mixture of two superfluids
• First and second sound in cylindrically trapped gases
• Faraday waves in elongated superfluid fermionic clouds
• Comment on ``Sound velocity and multibranch Bogoliubov spectrum of an elongated Fermi superfluid in the BEC-BCS crossover"
• Zero Sound and First Sound in a Disk-Shaped Normal Fermi gas
• First and second sound of a unitary Fermi gas in highly oblate harmonic traps
• Adiabatic sound velocity and compressibility of a trapped d-dimensional ideal anyon gas
• Shell Effects in the First Sound Velocity of an Ultracold Fermi Gas
• Hydrodynamic spectrum of a superfluid in an elongated trap
• Controlled acoustic-driven vortex transport in coupled superfluid rings
• Extreme dynamics and relaxation of quantum gases: A hydrodynamic approach