Speaker: Michael McNeil Forbes, Washington State University
Date & Time: March 31, 2014 12:00 - 13:00
Location: UBC, Hennings 318
Intended Audience: Graduate
In this talk I will tell the tale of a superfluid soliton. Starting its life as a phase imprinted domain wall in cold cloud of 6Li at MIT , it behaved mysteriously, moving an order of magnitude more slowly than expected. Using some of the largest computer simulations, we demonstrated  that the wall is rapidly promoted to a vortex ring that explains almost all aspects of the experiment, including some subtle effects due to the imaging process. Improved observations  reveal that the soliton is a vortex – the early retirement of the vortex ring induced by asymmetries present in the trap – and suggests that these experiments may provide an excellent forum for studying the microscopic nature of vortex crossing and recombination processes that like at the heart of quantum turbulence. The agreement between experiment and simulation validates the superfluid density functional theory (DFT), paving the road to understanding complex superfluid dynamics in cold atoms, nuclear matter, and neutron stars.