Dynamics of a Bose Condensate with Attractive Interactions
Abstract
A Bose-Einstein condensate composed of trapped atoms with negative scattering length exhibits remarkable dynamical behavior. The attractive mean-field interaction makes the condensate unstable when its occupation number is too large, causing it to implode; for ^7Li in our magnetic trap, the stability limit is about 1200 atoms.(C.C. Bradley et al.) Phys. Rev. Lett. 78, 985 (1997) When a collapse occurs, the density increases and the rate for inelastic collisions rises, eventually ejecting the condensate atoms from the trap. The condensate is then repopulated by the remaining uncondensed gas. This process gives rise to dynamical fluctuations in condensate number, which we have observed experimentally. These observations may reveal the probability for the collapse to be initiated by thermal excitation or macroscopic quantum tunneling out of the metastable configuration. Also, the question of whether any condensate atoms remain after the collapse depends critically on the details of the condensate dynamics, and is a current subject of theoretical debate. We will present our experimental results, and discuss models for these processes.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 1998
- Bibcode:
- 1998APS..DMP..B504S