Coulomb screening in mesoscopic noise: a kinetic approach

TL;DR

This paper investigates Coulomb screening effects on mesoscopic electronic noise using a kinetic approach, revealing two distinct mechanisms and their impact on fluctuations and noise, with implications for experimental detection.

Contribution

It introduces a kinetic framework analyzing Coulomb screening in mesoscopic noise, identifying two screening mechanisms and their effects on fluctuations and noise.

Findings

Two screening mechanisms identified: contact potential response and scattering coupling.

Contact potential effects renormalize thermal fluctuations at all scales.

Collisional effects influence non-equilibrium noise and are short-ranged.

Abstract

Coulomb screening, together with degeneracy, is characteristic of the metallic electron gas. While there is little trace of its effects in transport and noise in the bulk, at mesoscopic scales the electronic fluctuations start to show appreciable Coulomb correlations. Within a strictly standard Boltzmann and Fermi-liquid framework, we analyze these phenomena and their relation to the mesoscopic fluctuation-dissipation theorem, which we prove. We identify two distinct screening mechanisms for mesoscopic fluctuations. One is the self-consistent response of the contact potential in a non-uniform system. The other couples to scattering, and is an exclusively non-equilibrium process. Contact-potential effects renormalize all thermal fluctuations, at all scales. Collisional effects are relatively short-ranged and modify non-equilibrium noise. We discuss ways to detect these differences experimentally.