Synchronizability and mode-locking of two scaled quadratic maps via symmetric direct-coupling

The paper devotes to the synthesis of synchronizability and mode-locking of two scaled quadratic maps via symmetric direct-coupling. Present research shows that, similar to diffusive-coupling, the direct-coupling also admits all synchronized motions. Nevertheless, the synchronized motions are degenerated to the controlled dynamics instead of the pseudo-orbits of the local map. In consideration of chaos synchronization, nonlinear perturbations on the synchronized subspace are employed to perform the synchronization stability analysis. The synchronizability is also surveyed from a different perspective through investigating the synchronization of the coupled chaotic map in the presence of small parameter mismatch. The emergence of mode-locking phenomena in two-dimensional parameter space is secondary but proclaims the existence of incomplete synchronization.