Science 363, eaav7932 (2019)

Networks of coupled identical oscillators can settle into symmetric phase-locked synchronized states that are robust to underlying disorder. But what’s even more interesting is that they can be probed for the emergence of exotic broken-symmetry states. Pattern formation in biological systems, for example, arises from oscillations whose symmetry has clearly been broken, resulting in inhomogeneous phase distributions.

As Matthew Matheny and colleagues have now shown, such exotic states do not require precisely designed couplings, but can appear in a system as simple as eight nonlinear nanoelectromechanical oscillators with linear nearest-neighbour couplings. In the team’s experiments, when the oscillators’ mutual coupling was strong enough to require a description that went beyond first order, a plethora of states with exotic phase relations was observed — including travelling waves, weak chimeras and more. This wealth of states was reproduced theoretically by taking into account higher-order interactions, but will doubtless offer a treasure trove for theorists to come.