0000000001227658

AUTHOR

Lars Melwyn Jensen

showing 2 related works from this author

Fermion pairing with spin-density imbalance in an optical lattice

2006

We consider pairing in a two-component atomic Fermi gas, in a three-dimensional optical lattice, when the components have unequal densities, i.e. the gas is polarized. We show that a superfluid where the translational symmetry is broken by a finite Cooper pair momentum, namely an FFLO-type state, minimizes the Helmholtz free energy of the system. We demonstrate that such a state is clearly visible in the observable momentum distribution of the atoms, and analyze the dependence of the order parameter and the momentum distribution on the filling fraction and the interaction strength.

PhysicsCondensed Matter::Quantum GasesOptical latticeCondensed Matter - Materials ScienceCondensed matter physicsCondensed Matter - SuperconductivityGeneral Physics and AstronomyMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesFermion01 natural sciences114 Physical sciences010305 fluids & plasmasMomentumSuperfluiditySuperconductivity (cond-mat.supr-con)PairingCondensed Matter::Superconductivity0103 physical sciencesCooper pair010306 general physicsFermi gasTranslational symmetry
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BCS-BEC Crossover in Atomic Fermi Gases with a Narrow Resonance

2006

We determine the effects on the BCS-BEC crossover of the energy dependence of the effective two-body interaction, which at low energies is determined by the effective range. To describe interactions with an effective range of either sign, we consider a single-channel model with a two-body interaction having an attractive square well and a repulsive square barrier. We investigate the two-body scattering properties of the model, and then solve the Eagles-Leggett equations for the zero temperature crossover, determining the momentum dependent gap and the chemical potential self-consistently. From this we investigate the dependence of the crossover on the effective range of the interaction.

PhysicsCondensed Matter::Quantum GasesRange (particle radiation)Strongly Correlated Electrons (cond-mat.str-el)Condensed matter physicsNuclear TheoryCondensed Matter - SuperconductivityCrossoverFOS: Physical sciencesBCS theoryTwo-body problemResonance (particle physics)Atomic and Molecular Physics and OpticsSuperconductivity (cond-mat.supr-con)Nuclear Theory (nucl-th)MomentumCondensed Matter - Strongly Correlated ElectronsScattering theoryFermi gas
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