Quasiperiodic versus irreversible dynamics of an optically confined Bose-Einstein condensate - art. no. 033607

We consider the evolution of a dilute Bose-Einstein condensate in an optica l trap formed by a doughnut laser mode. By solving a one-dimensional Gross- Pitaevskii equation and looking at the variance and the statistical entropy associated with the position of the system, we can study the dynamical beh avior of the system. It is shown that for small condensates nonlinear reviv als of the macroscopic wave function are expected. For sufficiently large a nd dense condensates irreversible dynamics takes place for which revivals o f regular dynamics appear as predicted in P. Villain and M. Lewenstein, Phy s. Rev. A 62, 043601 (2000). These results are confirmed by a two-dimension al simulation in which the scales of energy associated with the two differe nt directions mimic the experimental situation.