Experiments on arrays of globally coupled chaotic electrochemical oscillators: Synchronization and clustering

Experiments on chaotically oscillating arrays of 64 nickel electrodes in su lfuric acid were carried out. External resistors in parallel and series are added to vary the extent of global coupling among the oscillators without changing the other properties of the system. The array is heterogeneous due to small variations in the properties of the electrodes and there is also a small amount of noise. The addition of global coupling transforms a syste m of independent elements to a state of complete synchronization. At interm ediate coupling strengths stable clusters, or condensates of elements, form . All the elements in a cluster follow the same chaotic trajectory but each cluster has its own dynamics; the system is thus temporally chaotic but sp atially ordered. Many cluster configurations occur under the same condition s and transitions among them can be produced. For values of the coupling pa rameter on either side of the stable cluster region a non-stationary behavi or occurs in which clustered and synchronized states alternately form and b reak up. Some statistical properties of the cluster states are determined. (C) 2000 American Institute of Physics. [S1054-1500(00)01601-3].