Fermionic superfluidity with positive scattering length
arXiv:cond-mat/0512472 · doi:10.1103/PhysRevA.74.023606
Abstract
Superfluidity in an ultracold Fermi gas is usually associated with either a negative scattering length, or the presence of a two-body bound state. We show that none of these ingredients is necessary to achieve superfluidity. Using a narrow Feshbach resonance with strong repulsive background interactions, the effective interactions can be repulsive for small energies and attractive for energies around the Fermi energy, similar to the effective interactions between electrons in a metallic superconductor. This can result in BCS-type superfluidity while the scattering length is positive.
6 pages, 3 figures; v2: added references and details energy-dependent interaction
References in corpus (23)
- Observation of resonance condensation of fermionic atom pairs
- Condensation of Pairs of Fermionic Atoms Near a Feshbach Resonance
- Observation of a Strongly-Interacting Degenerate Fermi Gas of Atoms
- Vortices and Superfluidity in a Strongly Interacting Fermi Gas
- Evidence for Superfluidity in a Resonantly Interacting Fermi Gas
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- Superfluid Fermi Gases with Large Scattering Length
- Equation of state of a Fermi gas in the BEC-BCS crossover: a quantum Monte Carlo study
- Resonance superfluidity in a quantum degenerate Fermi gas
- The BCS-BEC Crossover in a Gas of Fermi Atoms with a Feshbach Resonance
- Universal Thermodynamics of Degenerate Quantum Gases in the Unitarity Limit
- Fermi systems with long scattering lengths
- Three-boson problem near a narrow Feshbach resonance
- Atom-molecule coherence in Bose gases
- On the correct strong-coupling limit in the evolution from BCS superconductivity to Bose-Einstein condensation
- Resonance Superfluidity: Renormalization of Resonance Scattering Theory
- BCS-BEC crossover at finite temperature in the broken-symmetry phase
- The Nature of Superfluidity in Ultracold Fermi Gases Near Feshbach Resonances
- Feshbach resonances with large background scattering length: interplay with open-channel resonances
- A self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition
- Two-component Fermi gas with a resonant interaction
- Feshbach resonance in dense ultracold Fermi gases
- Resonance effects on the crossover of bosonic to fermionic superfluidity
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- Realization of a Resonant Fermi Gas with a Large Effective Range
- Alternative Route to Strong Interaction: Narrow Feshbach Resonance
- Total control over ultracold interactions via electric and magnetic fields
- Asymptotic Bound-state Model for Feshbach Resonances
- Orbital Feshbach Resonance: A "Wide" Narrow Resonance for Higher Transition Temperature Fermi Superfluid
- Two-band description of resonant superfluidity in atomic Fermi gases
- Dressed-molecules in resonantly-interacting ultracold atomic Fermi gases
- Generalized Crossover in Interacting Fermions within the Low-Energy Expansion