Transition to Phase Synchronization Through Generalized Synchronization

Synchronization in drive-response chaotic systems is studied. For a small mismatch of the natural frequency of the drive and response oscillators, phase synchronization comes before generalized synchronization. For moderate and even large parameter misfits, generalized synchronization can be achieved before phase synchronization. The mechanism of these two different bifurcations is interpreted in terms of the local-minimal-fluctuation method. It is found that the qualitative changes of local-minimal-fluctuations of the response system well manifests the appearance of generalized synchronization.