Defect-induced phase transition in the asymmetric simple exclusion process

We reconsider the long-standing question of the critical defect hopping rate r(c) in the one-dimensional totally asymmetric exclusion process (TASEP) with a slow bond (defect). For r < r(c) a phase-separated state is observed due to queuing at the defect site, whereas for r >= r(c) the defect site, has only local effects on the stationary state of the homogeneous system. Mean-field theory predicts r(c) = 1 (when hopping rates outside the defect bond are equal to 1) but numerical investigations seem to indicate r(c) approximate to 0.80 (2). Here we improve the numerics to show that r(c) > 0.99 and give strong evidence that indeed r(c) = 1 as predicted by mean-field theory, and anticipated by recent theoretical findings. Copyright (C) EPLA, 2015