'Anomalous' resurgence of shot noise in long conductors

There has been renewed interest in the physics of the so-called 'crossover' for current fluctuations in mesoscopic conductors, most recently involving the possibility of its appearance in the passage to the macroscopic limit. Shot noise is normally absent from solid-state conductors in the large, an d its anomalous resurgence there has been ascribed to a rich interplay of d rift, diffusion, and Coulomb screening. We demonstrate that essentially the same rise in short noise occurs in a much less complex system: the Boltzma nn-Drude-Lorentz model of a macroscopic, uniform gas of strictly non-intera cting carriers. We conclude that the 'anomalous crossover' is a manifestati on of simple kinetics. Poissonian carriers, if driven by a high enough fiel d cross the sample faster than any scattering time, thus fulfilling Schottk y's condition for ideal shot noise.