Experiments on an Ensemble of Globally and Nonlinearly Coupled Oscillators

In this paper we perform an experimental setup of the electronic oscillator ensemble with global and nonlinear coupling. Using the experimental setup with 72 units, we systematically analyze the ensemble dynamics for the cases of linear and nonlinear coupling. With an increase in the coupling strength we first observe formation and then destruction of a synchronous cluster, so that the dependence of the order parameter on the coupling strength is not monotonic. After destruction of the cluster the ensemble remains nevertheless coherent, i.e., it exhibits an oscillatory collective mode (mean field). We show that the system is now in a self-organized quasiperiodic state. In this state, frequencies of all oscillators are smaller than the frequency of the mean field, so that the oscillators are not locked to the mean field they create and their dynamics is quasiperiodic.