Collective Modes in a Unitary Fermi Gas across the Superfluid Phase Transition

Abstract

We provide a joint theoretical and experimental investigation of the temperature dependence of the collective oscillations of first sound nature exhibited by a highly elongated harmonically trapped Fermi gas at unitarity, including the region below the critical temperature for superfluidity. Differently from the lowest axial breathing mode, the hydrodynamic frequencies of the higher nodal excitations show a temperature dependence, which is calculated starting from Landau two-fluid theory and using the available experimental knowledge of the equation of state. The experimental results agree with high accuracy with the predictions of theory and provide the first evidence for the temperature dependence of the collective frequencies near the superfluid phase transition.

5 pages, 2 figures

References in corpus (9)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• Precision Measurements of Collective Oscillations in the BEC-BCS Crossover
• Virial expansion for a strongly correlated Fermi gas
• Collective oscillations of a Fermi gas in the unitarity limit: Temperature effects and the role of pair correlations
• Finite-Temperature Collective Dynamics of a Fermi Gas in the BEC-BCS Crossover
• First and second sound in a strongly interacting Fermi gas
• First and second sound in cylindrically trapped gases

Cited by in corpus (1)

• Scaling solutions of the two fluid hydrodynamic equations in a harmonically trapped gas at unitarity