Vortex dynamics in trapped Bose-Einstein Condensates
by
DrEnikö Madarassy(Uppsala University)
→
Europe/Stockholm
132:028
132:028
Description
We performed numerical simulations of various vortex configurations in a trapped Bose-Einstein condensate by solving the two-dimensional Gross-Pitaevskii equation in the presence of a simple model of interaction between the condensate and the finite temperature thermal cloud that surrounds it. In the case of a single vortex and a vortex-antivortex pair, we found that the path of the vortices depends on the initial separation distance and dissipation.
This motion was periodic and it was found that sound waves are created by vortex motion; the intensity was stronger when the initial vortex separation distance was smaller. We calculated the sound energy as the difference between the kinetic energy and the vortex energy. With no dissipation the vortices followed the same path with a slight oscillation due to the sound waves. We found that the smaller the initial vortex separation distance is, the larger the sound production.
The period, frequency, translation speed, sound energy and vortex energy were measured for different initial separation distances and for different dissipation parameters.
In the case of motion of one vortex, the connection between the dissipation and the friction coefficients of the vortex dynamics literature about superfluid helium was studied as well.
