Broad versus narrow Fano-Feshbach resonances in the BCS-BEC crossover with trapped Fermi atom

Abstract

With reference to the broad and narrow Fano-Feshbach resonances of 6Li at about 822 G and 543 G, we show that for the broad resonance a molecular coupled-channel calculation can be mapped with excellent accuracy onto an effective single-channel problem with a contact interaction. This occurs for a wide enough range of the magnetic field, that the full BCS-BEC crossover can be realized with a typical trap. For the narrow resonance, the mapping onto a single-channel problem and the realization of the BCS-BEC crossover are restricted to too narrow a range of the magnetic field to obtain them in practice. In this way, the BCS-BEC crossover for Fermi atoms with the broad resonance is placed on the same footing as the corresponding crossover for different physical systems.

Revised version to appear in Europhysics Letters

References in corpus (1)

• Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas

Cited by in corpus (5)

• Molecular Probe of Pairing in the BEC-BCS Crossover
• Extracting the condensate density from projection experiments with Fermi gases
• Popov approximation for composite bosons in the BCS-BEC crossover
• Comparison between a diagrammatic theory for the BCS-BEC crossover and Quantum Monte Carlo results
• Effective action for superfluid Fermi systems in the strong-coupling limit