# Imbalanced Fermi superfluid in a one-dimensional optical potential

## Abstract

The superfluid properties of a two-state Fermi mixture in an optical lattice are profoundly modified when an imbalance in the population of the two states is present. We present analytical solutions for the free energy and for the gap and number equations in the saddle-point approximation describing resonant superfluidity in the quasi-two-dimensional gas. Inhomogeneities due to the trapping potentials can be taken into account using the local-density approximation. Analyzing the free energy in this approximation, we find that phase separation occurs in the layers. The phase diagram of the superfluid and normal phases is derived, and analytical expressions for the phase lines are presented. We complete the investigation by accounting for effects beyond mean field in the Bose-Einstein condensate limit, where the system is more properly described as a Bose-Fermi mixture of atoms and molecules.

- Authors:

- TFVS, Universiteit Antwerpen, Groenenborgerlaan 171, B2020 Antwerpen (Belgium)

- Publication Date:

- OSTI Identifier:
- 20951422

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 18; Other Information: DOI: 10.1103/PhysRevB.75.184526; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANALYTICAL SOLUTION; BOSE-EINSTEIN CONDENSATION; DENSITY; FERMI GAS; FREE ENERGY; LAYERS; MEAN-FIELD THEORY; MIXTURES; ONE-DIMENSIONAL CALCULATIONS; PHASE DIAGRAMS; POTENTIALS; SUPERFLUIDITY; TRAPPING; TWO-DIMENSIONAL CALCULATIONS

### Citation Formats

```
Tempere, J., Wouters, M., and Devreese, J. T.
```*Imbalanced Fermi superfluid in a one-dimensional optical potential*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVB.75.184526.

```
Tempere, J., Wouters, M., & Devreese, J. T.
```*Imbalanced Fermi superfluid in a one-dimensional optical potential*. United States. doi:10.1103/PHYSREVB.75.184526.

```
Tempere, J., Wouters, M., and Devreese, J. T. Tue .
"Imbalanced Fermi superfluid in a one-dimensional optical potential". United States.
doi:10.1103/PHYSREVB.75.184526.
```

```
@article{osti_20951422,
```

title = {Imbalanced Fermi superfluid in a one-dimensional optical potential},

author = {Tempere, J. and Wouters, M. and Devreese, J. T.},

abstractNote = {The superfluid properties of a two-state Fermi mixture in an optical lattice are profoundly modified when an imbalance in the population of the two states is present. We present analytical solutions for the free energy and for the gap and number equations in the saddle-point approximation describing resonant superfluidity in the quasi-two-dimensional gas. Inhomogeneities due to the trapping potentials can be taken into account using the local-density approximation. Analyzing the free energy in this approximation, we find that phase separation occurs in the layers. The phase diagram of the superfluid and normal phases is derived, and analytical expressions for the phase lines are presented. We complete the investigation by accounting for effects beyond mean field in the Bose-Einstein condensate limit, where the system is more properly described as a Bose-Fermi mixture of atoms and molecules.},

doi = {10.1103/PHYSREVB.75.184526},

journal = {Physical Review. B, Condensed Matter and Materials Physics},

number = 18,

volume = 75,

place = {United States},

year = {Tue May 01 00:00:00 EDT 2007},

month = {Tue May 01 00:00:00 EDT 2007}

}