Dissipative dynamics of an open Bose Einstein condensate

As an atomic Bose Einstein condensate (BEC) is coupled to a source of uncon densed atoms at the same temperature and to a sink (extraction towards an a tom laser) the idealized description in terms of a Gross-Pitaevsky equation (GP) no longer holds. Under suitable physical assumptions we show that the dissipative BEC obeys a Complex Ginzburg Landau equation (CGL) and for som e parameter range it undergoes a space time patterning. As a consequence, t he density of BEC atoms within the trap displays non trivial space time cor relations, which can be detected by monitoring the density profile of the o utgoing atom laser. The patterning condition requires a negative scattering length, as e.g. in Li-7. In such a case we expect a many domain collapsed regime, rather than a single one as reported for a closed BEG. (C) 2000 Els evier Science B.V. All rights reserved.