Statistical Properties of Current Noise Induced by Electron-Phonon Scattering in Metallic Carbon Nanotubes

TL;DR

This paper analyzes the statistical properties of current noise in metallic carbon nanotubes caused by electron-phonon interactions, revealing a transition from Gaussian to gamma distributions and identifying non-Markovian effects in different transport regimes.

Contribution

It provides a detailed theoretical analysis of current noise distributions and their evolution across transport regimes in metallic carbon nanotubes, highlighting non-Gaussian features and non-Markovian dynamics.

Findings

PDF transitions from Gaussian to gamma distribution

Pronounced asymmetry in the crossover regime

Non-Markovian features dominate high-frequency noise in the diffusive regime

Abstract

We theoretically investigate current noise in metallic carbon nanotubes induced by electron-phonon scattering, focusing on the probability density function (PDF) of the current that characterizes the nonequilibrium steady state. Quantum transport simulations combined with analyses of higher-order statistical moments reveal that the PDF evolves continuously from a Gaussian distribution in the ballistic regime to a non-Gaussian gamma distribution in the diffusive regime. In the crossover regime, the PDF exhibits pronounced asymmetry, attributed to a statistical imbalance in the number of conduction pathways contributing to high- and low-current events. Furthermore, in the diffusive regime, we identify non-Markovian features arising from high-frequency resonances in the current noise, which dominate the asymptotic scaling behavior of the current variance.