Abstract

Symmetry breaking play a key role in equilibrium phase transitions, where low symmetry phases appear with lowering the temperature. Less is understood for driven-dissipative systems out of equilibrium, where the formations of symmetry broken states can be sometimes counterintuitive. First, this effect is illustrated for two Huygens pendulum clocks in the presence of strong nonlinearity. In this system, the synchronized motion of the oscillators at low driving regime is expected to bifurcate into symmetry broken dynamics, with the amplitude of one oscillator being larger than the amplitude of the other. Then, I will show that similar physics can take place for coupled condensates of non-equilibrium bosons or in driven dissipative lasing systems, in particular for condensates of exciton-polaritons, where the strong interactions lead to formation of specific many-body states. In particular, this results in period doubling, reduced symmetry of the condensate state with respect to the underlying potential, and to appearance of spontaneous currents. Finally, I will discuss the recent experimental observations of the symmetry breaking bifurcations in one-dimensional superlattices of exciton-polaritons and in polarization degree of freedom for trapped exciton-polariton condensates.