  We have investigated noise-induced transition of atoms between double or
triple phase-space attractors that are produced in the parametrically driven
magneto-optical trap. The transition rates between two or three dynamic
attractors, measured for various modulation frequencies and amplitudes, are in
good agreement with theoretical calculations and Monte-Carlo simulations based
on the Langevin equations. Our experiment may be useful to study nonlinear
dynamic problems involving transitions between states far from equilibrium.
