The total conductance G_L,R (solid curves) and the corresponding AR conductance G_A (dotted curves) in leads L (a) and R (b) through the double QDP chain versus the bias voltage eV for different Γ^L while Γ^R = 0.5. From bottom to top the curves are shifted up by 0.5e²/h in turn for clarity. The other parameters are taken to be λ_1,2 = 0.5, t₁ = 1, v_1,2 = 1, and ε_M = 0.