Collective collapse of a Bose-Einstein condensate with attractive interactions

Abstract

Bose-Einstein condensation (BEC) of atoms with attractive interactions is profoundly different from BEC of atoms with repulsive interactions, in several respects. We describe experiments with Bose condensates of 7Li atoms, which are weakly attracting at ultralow temperature. We measure the distribution of condensate occupation numbers occurring in the gas, which shows that the number is limited and demonstrates the dynamics of condensate growth and collapse.