Comment on ``Quantum Suppression of Shot Noise in Atom-Size Metallic Contacts''

TL;DR

This paper critiques a previous model of shot noise suppression in atomic gold contacts and demonstrates that a quantum-confined electron model with disorder better explains the experimental data.

Contribution

It introduces a quantum-confined electron model with disorder that accurately reproduces shot noise measurements in atomic gold contacts, improving upon prior ad hoc models.

Findings

Quantum-confined electron model matches experimental shot noise data.

Disorder plays a significant role in electronic transport at atomic scales.

Previous ad hoc models fail to fit the observed maxima and minima.

Abstract

In a recent letter (Phys.Rev.Lett. 82, 1526 (1999)), van den Brom and van Ruitenbeek found a pronounced suppression of the shot noise in atom-size gold contacts with conductances near integer multiples of $G_0=2e^2/h$, revealing unambiguously the quantized nature of the electronic transport. However, the ad hoc model they introduced to describe the contribution of partially-open conductance channels to the shot noise is unable to fit either the maxima or minima of their shot noise data. Here we point out that a model of quantum-confined electrons with disorder quantitatively reproduces their measurements.