Non-Equilibrium Universality in the Heating Dynamics of Interacting Luttinger Liquids

We establish a new non-equilibrium scaling regime in the short time evolution of one-dimensional interacting open quantum systems subject to a generic heating mechanism. This dynamical regime is characterized by uncompensated phonon production and a super-diffusive, universal scaling of quasiparticle lifetimes with momentum $\sim q^{-5/3}$, distinct from finite and zero temperature cases. It is separated from a high momentum regime by a time dependent scale fading out as $q_0(t) \sim t^{-4/5}$. In the latter region we observe thermalization to an effective time-dependent equilibrium with linearly increasing temperature. By mapping out the dynamical phase diagram and computing the dynamical structure factor within an open system Keldysh functional integral approach, we show how these predictions can be explored in cold atom experiments by means of Bragg spectroscopy.