BCS-BEC crossover in trapped Fermi gases

We study the spontaneous formation of vortices during superfluid condensation in a trapped fermionic gas subjected to a rapid thermal quench via evaporative cooling. Our work is based on the numerical solution of the time dependent crossover Ginzburg-Landau equation coupled to the heat diffusion equation. We quantify the evolution of condensate density and vortex length as a function of a crossover phase parameter from BCS to BEC. The more interesting phenomena occur somewhat nearer to the BEC regime and should be experimentally observable; during the propagation of the cold front, the increase in condensate density leads to the formation of supercurrents towards the center of the condensate as well as possible shock-wave generation.

Condensate.

3D time evolution of the condensate. Shown is only one quadrant of the whole system to visualize the interior of the condensate.

A. Glatz, H. Roberts, I. S. Aranson, K. Levin, Nucleation of spontaneous vortices in trapped Fermi gases undergoing a BCS-BEC crossover, Phys. Rev. B (R) 84, 180501 (2011).