Confinement controlled dissociation of a molecular Bose-Einstein condensate

We study the collective two-channel dissociation dynamics of a molecular Bose-Einstein condensate into bosonic fragments under tight harmonic confinement. Bose-stimulated dissociation in either channel can only take place provided that the respective trap size l_i for the fragments is large with respect to the healing length ζ_i of the atom-molecule resonance. Thus, even when both channels are equally coupled, differences in mass or in dynamical polarizability enable the control of the reaction outcome by variation of the trap frequency. In particular, if l₁ > ζ₁ and l₂ < ζ₂, only the first channel will be amplified. This behaviour demonstrates a unique feature of 'superchemistry' wherein a chemical reaction may be controlled by the manipulation of the reaction vessel.