Exciting, cooling, and vortex trapping in a Bose-condensed gas

A straightforward numerical technique, based on the Gross-Pitaevskii equation, is used to generate a self-consistent description of thermally excited states of a dilute boson gas. The process of evaporative cooling is then modeled by following the time evolution of the system using the same equation. It is shown that the subsequent rethermalization of the thermally excited state produces a cooler coherent condensate. Other results presented show that trapping vortex states with the ground state may be possible in a two-dimensional experimental environment. [S1050-2947(99)10802-3].