Jamming transition in an active exclusion process

Multiple studies on active matter have shown that activity can induce or suppress a phase transition, or modify the critical behavior of a passive system. Here we investigate how activity affects the jamming transition which is a paradigmatic example of nonequilibrium phase transitions in passive systems. We consider a one-dimensional system of active particles with hardcore interactions and a direction of self-propulsion which can be reversed at a given switching rate. For a class of particle hop rates and infinite switching rate, our model reduces to a passive system which is known to exhibit a transition between a high-density fluid phase and a low-density jammed phase in the stationary state. Using Monte Carlo simulations and a mean field theory, we study how the mean mobility of the particle and the hole cluster distribution vary with density and finite switching rate. Our main result is that activity hinders the formation of jam and can even inhibit it; more precisely, we find that the jamming transition occurs at a critical density that decreases with decreasing switching rate, and at sufficiently small switching rate, the system exists only in the fluid phase.