New universal quantities characterizing inhomogeneous Fermi gases at the Feshbach resonanceA. 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