Critical currents in the BEC/BCS crossover regime
arXiv:cond-mat/0508018 · doi:10.1103/PhysRevA.72.063601
Abstract
Both the trapping geometry and the interatomic interaction strength of a dilute ultracold fermionic gas can be well controlled experimentally. When the interactions are tuned to strong attraction, Cooper pairing of neutral atoms takes place and a BCS superfluid is created. Alternatively, the presence of Feshbach resonances in the interatomic scattering allows populating a molecular (bound) state. These molecules are more tightly bound than the Cooper pairs and can form a Bose-Einstein condensate (BEC). In this contribution, we describe both the BCS and BEC regimes, and the crossover, from a functional integral point of view. In this description, the properties of the superfluid (such as vortices and Josephson tunneling) can be derived and followed as the system is tuned from BCS the BEC. In particular, we present results for the critical current of the superfluid through an optical lattice and link these results to recent experiments with atomic bosons in optical lattices.
12 pages, 3 figures
References in corpus (18)
- Observation of resonance condensation of fermionic atom pairs
- Observation of a Strongly-Interacting Degenerate Fermi Gas of Atoms
- Vortices and Superfluidity in a Strongly Interacting Fermi Gas
- Observation of Bose-Einstein Condensation of Molecules
- Josephson Junction Arrays with Bose-Einstein Condensates
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- Interatomic collisions in a tightly confined Bose gas
- Molecular Probe of Pairing in the BEC-BCS Crossover
- Dynamical Superfluid-Insulator Transition in a Chain of Weakly Coupled Bose-Einstein Condensates
- Expansion of an interacting Fermi gas
- Superfluid current disruption in a chain of weakly coupled Bose-Einstein Condensates
- Crossover temperature of Bose-Einstein condensation in an atomic Fermi gas
- Path integral formulation of the tunneling dynamics of a superfluid Fermi gas in an optical potential
- Excitations of a Bose-Einstein condensate in a one-dimensional optical lattice
- The vortex state in the BEC to BCS crossover: a path-integral description
- Umklapp collisions and center of mass oscillation of a trapped Fermi gas
- Controllable Persistent Atom Current of Bose-Einstein Condensates in an Optical Lattice Ring
- Signatures of Superfluidity in Dilute Fermi Gases near a Feshbach Resonance