NONEQUILIBRIUM PHASE TRANSITIONS AND CRITICAL PHENOMENA FROM AdS/CFT

Abstract

We find novel phase transitions and critical phenomena that occur only outside the linear-response regime of current-driven nonequilibrium states, by using the AdS/CFT correspondence. We compute the nonlinear non-ballistic quark-charge conductivity of a strongly-interacting (3 + 1)-dimensional gauge theory, and we find that the system exhibits a nonequilibrium first-order and second-order phase transitions where the sign of the differential conductivity flips at finite current density. The present work provides a new example of nonequilibrium phase transitions and nonequilibrium critical points.