Discussion on the possibility of diffusive transport in mesoscopic conductors

We numerically investigate the conductance and the Fano factor in mesoscopic conductors, obtained by modulation doping in GaAs/AlGaAs heterostructures containing randomly located scatterers. In our simulations we represent these scatterers, deriving from the presence of randomly located impurities and dopants, either with hard-wall obstacles or with realistic potential fluctuations. Our results show that in mesoscopic devices it is quite unlikely to reach the diffusive regime, mainly due to the insufficient number of propagating modes.