Quantum Zeno control of spin mixing and squeezing in a spinor Bose–Einstein condensate

We study the effect of dephasing on the spin-mixing dynamics of a spinor Bose–Einstein condensate. We focus on a short-time dynamics and derive an analytical dynamics equations for the system by using mean-field approximation. We show the spin-mixing is suppressed via a quantum Zeno effect (QZE) in which the phase-noise intensity is much stronger than the inverse correlation time of the stimulated process. We also investigate the spin-nematic squeezing in the process of spin-mixing dynamics and show the squeezing is restrained by the QZE. (paper)