Temperature and coupling dependence of the universal contact intensity for an ultracold Fermi gas

Abstract

Physical properties of an ultracold Fermi gas in the temperature-coupling phase diagram can be characterized by the contact intensity C, which enters the pair-correlation function at short distances and describes how the two-body problem merges into its surrounding. We show that the local order established by pairing fluctuations about the critical temperature Tc of the superfluid transition considerably enhances the contact C in a temperature range where pseudogap phenomena are maximal. Our ab initio results for C in a trap compare well with recently available experimental data over a wide coupling range. An analysis is also provided for the effects of trap averaging on C.

arXiv comment5 pages, 5 figures

References in corpus (19)

• Large momentum part of fermions with large scattering length
• Energetics of a strongly correlated Fermi gas
• Observation of pseudogap behavior in a strongly interacting Fermi gas
• Exact Relations for a Strongly-interacting Fermi Gas from the Operator Product Expansion
• Verification of universal relations in a strongly interacting Fermi gas
• Pseudogap and spectral function from superconducting fluctuations to the bosonic limit
• Number of closed-channel molecules in the BEC-BCS crossover
• Universal Properties of the Ultra-Cold Fermi Gas
• BCS-BEC crossover at finite temperature in the broken-symmetry phase
• From the Bogoliubov-de Gennes equations for superfluid fermions to the Gross-Pitaevskii equation for condensed bosons
• Particle distribution tail and related energy formula
• Short-Time Operator Product Expansion for rf Spectroscopy of a Strongly-interacting Fermi Gas
• Radio-Frequency Transitions on Weakly-Bound Ultracold Molecules
• Universal Short-Distance Structure of the Single-Particle Spectral Function of Dilute Fermi Gases
• Enhanced paraconductivity-like fluctuations in the radio frequency spectra of ultracold Fermi atoms
• Molecular signatures in the structure factor of an interacting Fermi gas
• Short-range correlations and entropy in ultracold atomic Fermi gases
• Competition between final-state and pairing-gap effects in the radio-frequency spectra of ultracold Fermi atoms
• Popov approximation for composite bosons in the BCS-BEC crossover

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