Shot noise behavior of cascaded mesoscopic structures,

We discuss shot noise suppression in cascaded mesoscopic cavities, motivated by the discrepancy existing between analytical and numerical results published in the last few years. We conclude that the noise suppression factor does not increase above the 0.25 value for a single cavity only if all cavities are identical (a case in which it may even drop below 0.25), while, otherwise, increases toward the analytically predicted limit of 1/3, reaching even higher values. We comment on the numerical results, offering some possible explanations.