Dynamical Phase Transition from Nonequilibrium Dynamics of Dark Solitons

By holographic duality, we identify a novel dynamical phase transition which results from the temperature dependence of nonequilibrium dynamics of dark solitons in a superfluid. For a nonequilibrium superfluid system with an initial density of dark solitons, there exists a critical temperature T_{d}, above which the system relaxes to equilibrium by producing sound waves, while below which it goes through an intermediate phase with a finite density of vortex-antivortex pairs. In particular, as T_{d} is approached from below, the density of vortex pairs scales as (T_{d}-T)^{γ} with the critical exponent γ=1/2.