Macroscopic quantum tunneling of a Bose-Einstein condensate with attractive interaction: Fate of a false vacuum

Bosons interacting attractively with one another in a uniform system are believed not to undergo Bose-Einstein condensation (BEC) because they tend to collapse upon itself. However, when they are spatially confined, the zero-point kinetic pressure arising from Heisenberg's unceratin principle allows BEC to be formed in a metastable phase. By comparing various competing mechanisms such as collisional decay and fragmentation into pseudo-condensates, we show that near the critical point the decay of BEC will be dominated by macroscopic quantum tunneling.