Synchronization waves in arrays of driven chaotic systems

Chaotic synchronization has been observed experimentally and numerically in arrays of Chua's circuits, arranged in both linear and ring geometries, that are coupled by using the method recently introduced by G\"u\'emez and Mat\'{}as [Phys. Rev. E 52, R2145 (1995)]. For open linear geometries, the chaotic cells are seen to synchronize consecutively as a synchronization wave spreads through the array. Instead, for circular loops it is found that there is a critical number of cells above which the uniform synchronized state is not stable.