As an atomic Bose Einstein condensate (BEC) is coupled to a source of uncondensed atoms at the same temperature and to a sink (extraction towards an atom 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 some parameter range it undergoes a space time patterning. As a consequence, the density of BEC atoms within the trap displays non trivial space time correlations, which can be detected by monitoring the density profile of the outgoing atom laser. The patterning condition requires a negative scattering length, as e.g. in 7Li. In such a case we expect a many domain collapsed regime, rather than a single one as reported for a closed BEC.
- Pub Date:
- May 2000
- Condensed Matter - Mesoscale and Nanoscale Physics
- 13 pages, 5 figures, submitt. to Optics Comm., 18th Aug. 99 (special issue Scully Festschrift)