Can two scatterers offer less resistance than one?  (Datta Part B, Ch. 19, Figs. 19.2–19.9)

A 1D wire (t₀ = 1) with 51 sites; every contact is a self-energy Σ = −t₀e^ika on the end site (Sec. 19.1). Left: transmission T(E) for the chosen scatterers (crimson), one scatterer alone (grey) and the semiclassical result (green dashed). Right: the occupation f(j) = Gⁿ(j,j)/A(j,j) at the marked energy, a picture of the potential drop (Eq. 19.8). Click the left plot to choose E.