Phase synchronization with type-II intermittency in chaotic oscillators

We study the phase synchronization (PS) with type-II intermittency showing +/-2 pi irregular phase jumping behavior before the PS transition occurs in a system of two coupled hyperchaotic Rossler oscillators. The behavior is understood as a stochastic hopping of an overdamped particle in a potential which has 2 pi -periodic minima. We characterize it as type-II intermittency with external noise through the return map analysis. In epsilon (t)<<epsilon><<epsilon>(c) (where epsilon (t) is the bifurcation point of type-II intermittency and epsilon (c) is the PS transition point in coupling strength parameter space), the average length of the time interval between two successive jumps follows [l]similar to exp(/epsilon (t)-epsilon/(2)), which agrees well with the scaling law obtained from the Fokker-Planck equation.