Volume 80, Number 5, December 2007
Article Number 50002
Number of page(s) 6
Section General
Published online 25 October 2007
EPL, 80 (2007) 50002
DOI: 10.1209/0295-5075/80/50002

New universal quantities characterizing inhomogeneous Fermi gases at the Feshbach resonance

A. Csordás1, O. Almásy2 and P. Szépfalusy2, 3

1  HAS-ELTE Statistical and Biological Physics Research Group - Pázmány P. Sétány 1/A, H-1117 Budapest, Hungary
2  Department of Physics of Complex Systems, Eötvös University - Pázmány P. Sétány 1/A, H-1117 Budapest, Hungary
3  Research Institute for Solid State Physics and Optics - P.O. Box 49, H-1525 Budapest, Hungary

received 31 May 2007; accepted in final form 2 October 2007; published December 2007
published online 25 October 2007

Gradient corrections to the local density approximation are formulated for the density and the gap function in case of a spin-1/2 Fermi gas at unitarity. The related new universal numbers are calculated within the framework of the mean-field BCS model.

05.30.Fk - Fermion systems and electron gas.
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
74.20.Fg - BCS theory and its development.

© Europhysics Letters Association 2007