Effect of localization on the Fano factor of cascaded tunnel barriers

We study, by means of numerical and analytical quantum mechanical calcinations, shot noise suppression in a series of tunnel barriers, finding results that strongly differ from the 1/3 limit for the Fano factor that woidd be expected from semiclassical models. The reason for the observed residts is attributed to the presence of strong localization, which in the case of just one-dimensional disorder makes it impossible to reach the diffusive transport regime