Effect of Electron-RBM Phonon Interaction on Conductance of carbon nanotubes

TL;DR

This paper investigates how electron-RBM phonon interactions affect the electrical conductance of metallic zigzag carbon nanotubes, revealing step-like current behavior and temperature dependence, and proposes a method for phonon spectroscopy and CNT characterization.

Contribution

It introduces a perturbative energy analysis to study electron-RBM phonon effects on CNT conductance and suggests a new approach for phonon spectroscopy and nanotube characterization.

Findings

Conductance shows step-like dependence on bias voltage.

Temperature influences conductance at different bias levels.

Method enables phonon spectroscopy and CNT structural analysis.

Abstract

We use the energy analysis as a perturbative method to study the effect of electron-radial breathing mode (RBM) phonon interaction on the electrical conductivity of long metallic zigzag carbon nanotubes (CNTs). The band structure of zigzag CNTs is calculated by exerting zone-folding method on relations derived by using the nearest neighbor approximation of tight-binding expression for the $\pi$ valence and conduction bands of graphene. The small hollow cylinder model, with two different approximations, is used to obtain the RBM frequency in our calculation. As the result, we have calculated the effects of electron$ - $RBM phonon interaction on the conductance of zigzag CNTs. It has been observed that current is a step$ - $like function of bias voltage because of the absorption or emission by electron injection in the system. Moreover, the dependence of the conductance to the temperature in low bias and high bias voltages has been studied. In this paper, we propose a simple and useful method for phonon spectroscopy. Also, since RBM mode determines the geometry and structure of CNT, this approach can be used for characterization of CNTs.