Asymmetric coupling in two-lane simple exclusion processes: Effect of unequal injection rates

This Letter investigates the effect of unequal injection rates on two-lane simple exclusion processes with asymmetric coupling. It is a generalization of the work of Pronina and Kolomeisky [E. Pronina, A.B. Kolomeisky, Physica A 372 (2006) 12], in which the injection rates of two lanes are equal. With the injection rate α1α1 increases, the (1,LD)(1,LD), (1,HD)(1,HD), (1,MC)(1,MC) and (MC,MC)(MC,MC) phase region do not change, while the (LD,0)(LD,0) phase regions shrink and the (HD,0)(HD,0) and (MC,0)(MC,0) phase regions expand. Interestingly, domain walls are observed in both lanes when the system is in the (MC,MC)(MC,MC) phase. However, the unequal injection rates have little effect on the domain wall dynamics. The phase diagram and the density profiles are investigated by using Monte Carlo simulations and mean-field approximation. The analytical results are in good agreement with simulations.