Discussion of Shot Noise Suppression in Cascaded Mesoscopic Cavities

In this contribution we discuss the issue of shot noise suppression in cascaded mesoscopic cavities, which presents some still puzzling aspects that require further investigation. While a semiclassical model would predict, assuming a few idealized hypotheses, that the Fano factor for a series of cavities should tend to 1/3 as the number of cavities increases, a numerical quantum calculation yields analogous results for unequal cavities (although with a tendency to overcome the 1/3 value) and sharply different results for identical cavities, for which the Fano factor is found to be the same as that of a single cavity or even lower. We present and discuss a series of numerical results obtained with a recursive Green's function approach, trying to find clues to a general understanding of the problem.