Quantum Zeno control of coherent dissociation

We study the effect of dephasing on the coherent dissociation dynamics of an atom-molecule Bose-Einstein condensate. We show that when phase-noise intensity is strong with respect to the inverse correlation time of the stimulated process, dissociation is suppressed via a Bose enhanced Quantum Zeno effect. This is complementary to the quantum zeno control of phase-diffusion in a bimodal condensate by symmetric noise (Phys. Rev. Lett. {\bf 100}, 220403 (2008)) in that the controlled process here is phase-{\it formation} and the required decoherence mechanism for its suppression is purely phase noise.