Pair excitations and parameters of state of imbalanced Fermi gases at finite temperatures

Abstract

The spectra of low-lying pair excitations for an imbalanced two-component superfluid Fermi gas are analytically derived within the path-integral formalism taking into account Gaussian fluctuations about the saddle point. The spectra are obtained for nonzero temperatures, both with and without imbalance, and for arbitrary interaction strength. On the basis of the pair excitation spectrum, we have calculated the thermodynamic parameters of state of cold fermions and the first and second sound velocities. The parameters of pair excitations show a remarkable agreement with the Monte Carlo data and with experiment.

14 pages, 5 figures

References in corpus (16)

• Many-Body Physics with Ultracold Gases
• Thermodynamics of the BCS-BEC crossover
• Imbalanced Feshbach-resonant Fermi gases
• Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover
• Universal properties of a trapped two-component Fermi gas at unitarity
• Energetics and Structural Properties of Trapped Two-Component Fermi Gases
• Temperature of a trapped unitary Fermi gas at finite entropy
• First and second sound in a strongly interacting Fermi gas
• The effect of population imbalance on the Berezinskii-Kosterlitz-Thouless phase transition in a superfluid Fermi gas
• Propagation of Second sound in a superfluid Fermi gas in the unitary limit
• Low-temperature thermodynamics of the unitary Fermi gas: superfluid fraction, first sound and second sound
• Phase separation in imbalanced fermion superfluids beyond mean-field
• Surface Effects in the Unitary Fermi Gas
• Imbalanced d-wave superfluids in the BCS-BEC crossover regime at finite temperatures
• Stability of Inhomogeneous Multi-Component Fermi Gases
• Spin-polarized Fermi superfluids as Bose-Fermi mixtures

Cited by in corpus (14)

• Pseudogap and preformed pairs in the imbalanced Fermi gas in two dimensions
• Three-phonon and four-phonon interaction processes in a pair-condensed Fermi gas
• Thermal blurring of a coherent Fermi gas
• Beliaev damping of the Goldstone mode in atomic Fermi superfluids
• Absorption and emission of a collective excitation by a fermionic quasiparticle in a Fermi superfluid
• Landau-Khalatnikov phonon damping in strongly interacting Fermi gases
• Collective modes in the anisotropic unitary Fermi gas and the inclusion of a backflow term
• Dynamical properties of the unitary Fermi gas: collective modes and shock waves
• Dispersive effects in the unitary Fermi gas
• Low-energy modes of spin-imbalanced Fermi gases in BCS phase
• Damping of the Anderson-Bogolyubov mode by spin and mass imbalance in Fermi mixtures
• Unitary Fermi superfluid near the critical temperature: thermodynamics and sound modes from elementary excitations
• Anderson-Bogoliubov collective excitations in superfluid Fermi gases at nonzero temperatures
• Pair condensation of polarized fermions in the BCS-BEC crossover