Growth of a Bose-Einstein condensate: A detailed comparison of theory and experiment

We extend the earlier model of condensate growth of Davis et al [Davis MJ, Gardiner CW and Ballagh RJ 2000 Phys. Rev. A 62 063608] to include the effect of gravity in a magnetic trap. We carry out calculations to model the experiment reported by Köhl et al [Köhl M, Davis MJ, Gardiner CW, Hänsch T and Esslinger T, Preprint cond-mat/0106642] who study the formation of a rubidium Bose-Einstein condensate for a range of evaporative cooling parameters. We find that in the regime where our model is valid, the theoretical curves agree with all the experimental data with no fitting parameters. However, for the slowest cooling of the gas the theoretical curve deviates significantly from the experimental curves. It is possible that this discrepancy may be related to the formation of a quasicondensate.