Fig. 1. A schematic diagram of synchronization of coupled oscillators: (a) Most of the oscillators are asynchronous and evenly distributed along the circle; (b) with increasing the coupling, more and more oscillators are synchronized and are no longer evenly distributed; (c) under a strong coupling, oscillators form a single synchronous cluster, and the phases of oscillators are close to each other; (d) dependence of the order parameter on the coupling strength

Fig. 2. The Poincare section of the order parameter α in phase space, where one can find the closed tori and chaotic scattered points.