Non-BCS superfluidity in trapped ultracold Fermi gases
arXiv:cond-mat/0604424 · doi:10.1103/PhysRevA.76.033620
Abstract
Superconductivity and superfluidity of fermions require, within the BCS theory, matching of the Fermi energies of the two interacting Fermion species. Difference in the number densities of the two species leads either to a normal state, to phase separation, or - potentially - to exotic forms of superfluidity such as FFLO-state, Sarma state or breached pair state. We consider ultracold Fermi gases with polarization, i.e. spin-density imbalance. We show that, due to the gases being trapped and isolated from the environment in terms of particle exchange, exotic forms of superfluidity appear as a shell around the BCS-superfluid core of the gas and, for large density imbalance, in the core as well. We obtain these results by describing the effect of the trapping potential by using the Bogoliubov-de Gennes equations. For comparison to experiments, we calculate also the condensate fraction, and show that, in the center of the trap, a polarized superfluid leads to a small dip in the central density difference. We compare the results to those given by local density approximation and find qualitatively different behavior.
arXiv commentExtended and revised, 13 pages, 13 figures
References in corpus (37)
- Pairing and Phase Separation in a Polarized Fermi Gas
- Fermionic Superfluidity with Imbalanced Spin Populations and the Quantum Phase Transition to the Normal State
- Inhomogeneous Superconductivity in Condensed Matter and QCD
- Observation of Phase Separation in a Strongly-Interacting Imbalanced Fermi Gas
- Interior Gap Superfluidity
- Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases
- BEC-BCS crossover in "magnetized" Feshbach-resonantly paired superfluids
- Phase separation in asymmetrical fermion superfluids
- Deformation of a Trapped Fermi Gas with Unequal Spin Populations
- Normal state of a polarized Fermi gas at unitarity
- Renormalization of the Hartree-Fock-Bogoliubov Equations in the Case of a Zero Range Pairing Interaction
- Pairing without Superfluidity: The Ground State of an Imbalanced Fermi Mixture
- Stability Criteria for Breached Pair Superfluidity
- Direct Imaging of Spatially Modulated Superfluid Phases in Atomic Fermion Systems
- BCS Theory for Trapped Ultracold Fermions
- Strongly interacting Fermi gases with density imbalance
- Breached pairing superfluidity: Possible realization in QCD
- Induced P-wave Superfluidity in Asymmetric Fermi Gases
- Generic Phase Diagram of Fermion Superfluids with Population Imbalance
- Profiles of near-resonant population-imbalanced trapped Fermi gases
- Trapped fermions with density imbalance in the BEC limit
- Pairing in a two-component ultracold Fermi gas: phases with broken space symmetries
- Sarma Phase in Trapped Unbalanced Fermi Gases
- Trapped Fermions across a Feshbach resonance with population imbalance
- Condensate Fraction of a Fermi Gas in the BCS-BEC Crossover
- Surface Tension in Unitary Fermi Gases with Population Imbalance
- Pairing of a trapped resonantly-interacting fermion mixture with unequal spin populations
- Single-particle excitations in a trapped gas of Fermi atoms in the BCS-BEC crossover region
- Non-standard pairing in asymmetric trapped Fermi gases
- Mean field thermodynamics of a spin-polarized spherically trapped Fermi gas at unitarity
- Hartree-Fock-Bogoliubov theory versus local-density approximation for superfluid trapped fermionic atoms
- Breakdown of the local density approximation in interacting systems of cold fermions in strongly anisotropic traps
- Shrinking of a condensed fermionic cloud in a trap approaching the BEC limit
- Normal-Superfluid Interface Scattering For Polarized Fermion Gases
- Finite temperature effects in trapped Fermi gases with population imbalance
- Homogeneous Fermion Superfluid with Unequal Spin Populations
- Response to Comment on "Pairing and Phase Separation in a Polarized Fermi Gas"
Cited by in corpus (17)
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- Imbalanced Feshbach-resonant Fermi gases
- The Fulde-Ferrell-Larkin-Ovchinnikov state for ultracold fermions in lattice and harmonic potentials: a review
- Imbalanced Fermi Gases at Unitarity
- FFLO state in 1, 2, and 3 dimensional optical lattices combined with a non-uniform background potential
- Thermodynamics and superfluid density in BCS-BEC crossover with and without population imbalance
- Fulde-Ferrell states and Berezinskii-Kosterlitz-Thouless phase transition in two-dimensional imbalanced Fermi gases
- Exotic superfluid states of lattice fermions in elongated traps
- Hartree shift in unitary Fermi gases
- Theory of the Normal/Superfluid interface in population imbalanced Fermi gases
- Population imbalanced fermions in harmonically trapped optical lattices
- Rotation induced superfluid-normal phase separation in trapped Fermi gases
- Dimensional Crossover in a Spin-imbalanced Fermi gas
- Density response of a trapped Fermi gas: a crossover from the pair vibration mode to the Goldstone mode
- Spin-imbalanced ultracold Fermi gases in a two-dimensional array of tubes
- Transport of Spin and Mass at Normal-Superfluid Interfaces in the Unitary Fermi Gas
- Trap and population imbalanced two-component Fermi gas in the BEC limit