Roberts J L, Claussen N R, Cornish S L, Donley E A, Cornell E A, Wieman C E
JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA.
Phys Rev Lett. 2001 May 7;86(19):4211-4. doi: 10.1103/PhysRevLett.86.4211.
The point of instability of a Bose-Einstein condensate (BEC) due to attractive interactions was studied. Stable 85Rb BECs were created and then caused to collapse by slowly changing the atom-atom interaction from repulsive to attractive using a Feshbach resonance. At a critical value, an abrupt transition was observed in which atoms were ejected from the condensate. By measuring the onset of this transition as a function of number and attractive interaction strength, we determined the stability condition to be N(absolute value of a) / a(ho) = 0.459+/-0.012+/-0.054, slightly lower than the predicted value of 0.574.
