Observable nonclassical correlation effects in the dynamics of a bidimensionally confined ion

The occurrence of a peculiar correlation effect in the quantum dynamics ofan ion confined in a 2D Paul microtrap is reported. We analytically find that when the ion, prepared in a SU(2) vibrational coherent state, is irradiated by two orthogonal laser beams, the time evolution of the quantum covariance between two clearly interpretable bosonic observables displays an high sensitivity to the initial state parameters. Both the nonclassical natureof this effect and a simple proposal for its detection is briefly discussed.