Order parameter |⟨ n
⟩|/ N for the case I = P in the symmetric circuit. The modulus |·| folds the two symmetric branches (corresponding to the two stationary state distributions) into one. The solid curves show the analytical results from the mean-field theory and the symbols represent simulations. J + 1 = [5, 10, 100] is shown in [blue, green, red] for the mean-field theory and as [+, o, ×] for simulations. Target molecule numbers used in the simulations are, respectively, N = [4000, 2000, 400].