Long-Range Coulomb Interaction and Frequency Dependence of Shot Noise in Mesoscopic Diffusive Contacts

TL;DR

This paper investigates how long-range Coulomb interactions and external screening influence the frequency-dependent shot noise in mesoscopic diffusive contacts, revealing distinct behaviors at low and high frequencies.

Contribution

It provides a theoretical analysis of shot noise frequency dependence considering Coulomb interactions and screening effects in mesoscopic diffusive systems.

Findings

Low-frequency noise is 1/3 of classical Poisson noise, regardless of contact shape.

High-frequency noise approaches the classical value for long, narrow contacts.

Screening causes current fluctuations at opposite ends of the contact to become independent.

Abstract

The frequency dependence of shot noise in mesoscopic diffusive contacts is calculated with account taken of long-range Coulomb interaction and external screening. While the low-frequency noise is 1/3 of noise of classical Poisson process independently of the contact shape, the high-frequency noise tends to the full classical value for long and narrow contacts because of strong screening by the surrounding medium. In this case, the current fluctuations at opposite ends of the contact are completely independent.