Kinetics of Bose-Einstein Condensation in a Trap

The formation process of a Bose-Einstein condensate in a trap is described using a master equation based on quantum kinetic theory, which can be well approximated by a description using only the condensate mode in interaction with a thermalized bath of noncondensate atoms. A rate equation of the form \. {}n{0ex{0ex}=0ex{0ex}2W}^+ (n) (1-e^{{₍-}/kT}) n+1 is derived, in which the difference between the condensate chemical potential ₍ and the bath chemical potential gives the essential behavior. Solutions of this equation give a characteristic latency period for condensate formation and appear to be consistent with the observed behavior of both rubidium and sodium condensate formation.