Equivalent resistance and noise of cascaded mesoscopic cavities

SUMMARYSince the time of the early studies on mesoscopic devices, it was recognized that, due mainly to theballistic nature of transport, their resistances and the other electrical quantities could not be combinedfollowing the traditional rules of circuit theory. Here, we focus specifically on the conductance and noiseresulting from a chain of cascaded mesoscopic cavities and discuss an existing semiclassical model forconductance and shot noise, recasting it into an equivalent circuit description. Numerical simulations showthat such a model fails if the cavities are identical and is only partially valid if cavities are unequal. Wediscuss possible explanations for such a somewhat surprising behaviour. Copyright q 2007 John Wiley& Sons, Ltd. Received 20 February 2007KEY WORDS : mesoscopic cavities; chaotic cavities; noise in mesoscopic devices; Fano factor INTRODUCTIONAs soon as fabrication of high-mobility mesoscopic devices became possible, as a result of thedefinition of quasi-1D channels on GaAs