Pseudo-gap pairing in ultracold Fermi atoms

Abstract

The crossover from a BEC (Bose-Einstein condensation) to a BCS (Bardeen-Cooper-Schrieffer) superfluid in dilute gases of ultracold Fermi atoms creates an ideal environment to enrich our knowledge of strongly correlated many-body systems. These experiments are relevant to a wide range of fields from condensed matter to astrophysics. The nature of pairing in strongly interacting Fermi gases can be readily studied, thus aiding our understanding of related problems in high-T_{c} superconductors, whose mechanism is still under debate. These are not well-understood due to the large interaction parameter. Here, we calculate the dynamical properties of a normal, trapped, and strongly correlated Fermi gas, by developing a quantum cluster expansion. In ultra-cold atomic physics one can measure the elementary excitations, using rf or Bragg spectroscopy. Our calculations for the single-particle spectral function agree with the recent measurements, and clearly demonstrate pseudogap pairing in the strongly interacting regime.

4 pages, 4 figures; add comparison with the JILA pseudogap measurement (Nature Physics); published version in Phys. Rev. Lett

References in corpus (8)

• Theory of ultracold Fermi gases
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• Bragg spectroscopy of a strongly interacting Fermi gas
• Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
• Virial expansion for a strongly correlated Fermi gas
• Measurement of the Entropy and Critical Temperature of a Strongly Interacting Fermi Gas
• Bragg Spectroscopy of Cold Atomic Fermi Gases

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• Static structure factor of a strongly correlated Fermi gas at large momenta
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• Quantitative comparison between theoretical predictions and experimental results for Bragg spectroscopy of a strongly interacting Fermi superfluid
• Virial expansion for a strongly correlated Fermi gas with imbalanced spin populations
• High temperature thermodynamics of strongly interacting s-wave and p-wave Fermi gases in a harmonic trap
• Pairing and radio-frequency spectroscopy in two-dimensional Fermi gases
• Sigature of the universal super Efimov Effect: three-body contact in two dimensional Fermi gases
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• Momentum-resolved spectroscopy of a Fermi liquid
• Thermodynamic Properties of Rashba Spin-Orbit-Coupled Fermi Gas
• Dynamic structure factor of a strongly correlated Fermi superfluid within a density functional theory approach
• Low-Dimensional Fluctuations and Pseudogap in Gaudin-Yang Fermi Gases
• Many-body theories of density response for a strongly correlated Fermi gas
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• Pseudogap phenomena near the BKT transition of a two-dimensional ultracold Fermi gas in the crossover region
• Normal-state Properties of a Unitary Bose-Fermi Mixture: A Combined Strong-coupling Approach with Universal Thermodynamics