In this talk I will discuss the emergence of novel universal behaviour in one-dimensional driven open quantum systems, in the presence of diffusive Markovian noise. Salient features are the persistence of both non-equilibrium conditions as well as quantum coherence close to criticality. This provides a non-equilibrium analogue of quantum criticality, and it is sharply distinct from more generic driven systems, where both effective thermalization as well as asymptotic decoherence ensue, paralleling classical dynamical criticality. I will also provide a non-technical overview of the functional renormalization group method suited to the Keldysh action, which allows to extract the full set of independent critical exponents necessary to characterise the novel non equilibrium quantum universality class. Reference: J. Marino, S. Diehl, Phys. Rev. Lett. 116, 070407 (2016)

Institute for Theoretical Physics – University of Cologne