Superfluidity in atomic Fermi gases

Abstract

In a trapped atomic Fermi gas, one can tune continuously via a Feshbach resonance the effective pairing interaction between fermionic atoms from very weak to very strong. As a consequence, the low temperature superfluidity evolves continuously from the BCS type in the weak interaction limit to that of Bose-Einstein condensation in the strong pairing limit, exhibiting a BCS-BEC crossover. In this paper, we review recent experimental progress in atomic Fermi gases which elucidates the nature of the superfluid phase as the interaction is continuously tuned. Of particular interest is the intermediate or crossover regime where the $s$-wave scattering length diverges. We will present an intuitive pairing fluctuation theory, and show that this theory is in quantitative agreement with existing experiments in cold atomic Fermi gases.

4 pages, 4 figures in color, invited talk at the M2S-IX Tokyo conference, September 2009

References in corpus (7)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• Molecular Probe of Pairing in the BEC-BCS Crossover
• Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases
• Pairing without Superfluidity: The Ground State of an Imbalanced Fermi Mixture
• Final-state effects in the radio frequency spectrum of strongly interacting fermions