A Rapidly Expanding Bose-Einstein Condensate: An Expanding Universe in the Lab
A Rapidly Expanding Bose-Einstein Condensate: An Expanding Universe in the Lab
We study the dynamics of a supersonically expanding, ring-shaped Bose-Einstein condensate both experimentally and theoretically. The expansion redshifts long-wavelength excitations, as in an expanding universe. After expansion, energy in the radial mode leads to the production of bulk topological excitations—solitons and vortices—driving the production of a large number of azimuthal …