Semiclassical theory of shot-noise suppression

TL;DR

This paper develops a semiclassical model using the Boltzmann-Langevin equation to explain shot-noise suppression in mesoscopic conductors, showing the universal one-third suppression in diffusive systems without phase coherence.

Contribution

It introduces a semiclassical approach to shot-noise suppression, demonstrating the one-third suppression in tunneling through many barriers without relying on quantum phase coherence.

Findings

Shot noise approaches one-third of Poisson noise as barriers increase.

Suppression is independent of barrier transparency.

Confirms phase coherence is not necessary for one-third suppression.

Abstract

The Boltzmann-Langevin equation is used to relate the shot-noise power of a mesoscopic conductor to classical transmission probabilities at the Fermi level. This semiclassical theory is applied to tunneling through n barriers in series. For n -> infinity the shot noise approaches one third of the Poisson noise, independent of the transparency of the barriers. This confirms that the one-third suppression known to occur in diffusive conductors does not require phase coherence.