Temperature dependence of the pair coherence and healing lengths for a fermionic superfluid throughout the BCS-BEC crossover

Abstract

We calculate the pair correlation function and the order parameter correlation function, which probe, respectively, the intra-pair and inter-pair correlations of a Fermi gas with attractive inter-particle interaction, in terms of a diagrammatic approach as a function of coupling throughout the BCS-BEC crossover and of temperature, both in the superfluid and normal phase across the critical temperature $T_c$. Several physical quantities are obtained from this calculation, including the pair coherence and healing lengths, the Tan's contact, the crossover temperature $T^{\ast }$ below which inter-pair correlations begin to build up in the normal phase, and the signature for the disappearance of the underlying Fermi surface which tends to survive in spite of pairing correlations. A connection is also made with recent experimental data on the temperature dependence of the normal coherence length as extracted from the proximity effect measured in high-temperature (cuprate) superconductors.

22 pages, 15 figures

References in corpus (8)

• Thermodynamics of the BCS-BEC crossover
• Bold Diagrammatic Monte Carlo: When Sign Problem is Welcome
• BCS-BEC crossover at finite temperature in the broken-symmetry phase
• Determination of the Fermion Pair Size in a Resonantly Interacting Superfluid
• Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas
• Enhanced paraconductivity-like fluctuations in the radio frequency spectra of ultracold Fermi atoms
• Temperature and coupling dependence of the universal contact intensity for an ultracold Fermi gas
• Virial expansion for a strongly correlated Fermi gas with imbalanced spin populations

Cited by in corpus (9)

• Density correlation functions and the spatial structure of the two-dimensional BEC-BCS crossover
• Spatial emergence of Off-Diagonal Long-Range Order throughout the BCS-BEC crossover
• Non-local equation for the superconducting gap parameter
• Nambu-Covariant Many-Body Theory II: Self-Consistent Approximations
• Peaks and widths of radio-frequency spectra: An analysis of the phase diagram of ultra-cold Fermi gases
• Reliability of the Ginzburg-Landau Theory in the BCS-BEC Crossover by Including Gaussian Fluctuations for 3D Attractive Fermions
• Vortex Mass in Superfluid Fermi Gases along the BEC-BCS Crossover
• Effect of Population Imbalance on Vortex Mass in Superfluid Fermi Gases
• Strong Fulde-Ferrell Larkin-Ovchinnikov pairing fluctuations in polarized Fermi systems