Activated nucleation of vortices in a dipole-blockaded supersolid condensate

Phys Rev Lett. 2012 Jul 27;109(4):045301. doi: 10.1103/PhysRevLett.109.045301. Epub 2012 Jul 23.

Abstract

We investigate theoretically and numerically a model of a supersolid in a dipole-blockaded Bose-Einstein condensate. The dependence of the superfluid fraction with an imposed thermal bath and a uniform boost velocity on the condensate is considered. Specifically, we observe a critical velocity for the nucleation of vortices in our system that is strongly linked to a steplike decrease in the superfluid fraction. We are able to use a scaling argument based on the energy required to activate a vortex, relating the critical temperature to the critical velocity, and find that this relationship is in good agreement with the numerical simulations carried out on the nonlocal Gross-Pitaevskii equation.