Chimera states in mechanical oscillator networks.
The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature uses to orchestrate essential processes of life, such as the beating of the heart. Although it was long thought that synchrony and disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of "chimera states," in which the symmetry of the oscillator population is broken into a synchronous part and an asynchronous part. However, a striking lack of empirical evidence raises the question of whether chimeras are indeed characteristic of natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patterns. We identify a wide spectrum of complex states, encompassing and extending the set of previously described chimeras. Our mathematical model shows that the self-organization observed in our experiments is controlled by elementary dynamical equations from mechanics that are ubiquitous in many natural and technological systems. The symmetry-breaking mechanism revealed by our experiments may thus be prevalent in systems exhibiting collective behavior, such as power grids, optomechanical crystals, or cells communicating via quorum sensing in microbial populations.
['Martens|Erik Andreas|EA|', 'Thutupalli|Shashi|S|', 'Fourrière|Antoine|A|', 'Hallatschek|Oskar|O|']
D000818:Animals D001683:Biological Clocks D001696:Biomechanical Phenomena D055592:Biophysical Phenomena D006801:Humans D008954:Models, Biological D008962:Models, Theoretical D017711:Nonlinear Dynamics D009991:Oscillometry D055585:Physical Phenomena D053038:Quorum Sensing
ensemble dynamics nonlinear dynamics statistical physics