Nonequilibrium Phase Transitions in Gauge-Theory Plasma

We report an AdS/CFT analysis that indicates new types of current-driven nonequilibrium phase transitions in a gauge-theory plasma. What we compute is the differential conductivity of the gauge-theory plasma that can be either negative or positive depending on the parameters of the system. We find that the transition from negative differential conductivity to positive differential conductivity is not always crossover but can be a first-order-like discontinuous transition. A second-order-like transition where the differential resistivity diverges is also found at the boundary between the first-order regime and the crossover regime. These transitions occur only outside the linear-response regime of the nonequilibrium systems.