Dynamic vibration phase reversal transition in discrete time-translational symmetry broken cold atoms

We experimentally demonstrate vibration phase reversal transition in a discrete time-translational symmetry broken cold atomic system by the application of a pulsed bias-field opposite to the existing phase of the symmetry broken vibrational state. The reversal transition depends on the strength hp and the duration Δt of the applied pulse. Consequently, we obtain a hp−Δt phase boundary with a divergent relaxation time τ due to the critical slowdown behavior. Interestingly, the dependence of the dynamic phase boundary and relaxation time on the noise-induced switching rate implies that the system is out of equilibrium, though not so in the Ising model of a spin system.