Single-mode phonon transmission in symmetry broken carbon nanotubes

TL;DR

This study investigates how Stone-Wales defects in carbon nanotubes affect phonon transmission, revealing that symmetry breaking significantly reduces transmission of certain phonons, impacting thermal transport and local heating.

Contribution

It provides a detailed analysis of phonon transmission alterations due to symmetry breaking caused by Stone-Wales defects in carbon nanotubes.

Findings

Reduced transmission of low group velocity acoustic phonons at high frequencies

Strong inhibition of long wave optical phonons transmission

Transmission characteristics depend on phonon mode symmetry

Abstract

Normal mode phonon transmissions are studied in carbon nanotubes with the presence of Stone-Wales (SW) defect, using a mode-matching method and through the analysis of symmetry. The calculation shows that the transmission for low group velocity acoustic phonons is evidently reduced at high frequency range, and that this SW defect induced symmetry breaking strongly inhibits the transmission of long wave optical phonons in carbon nanotubes. The characteristic features of transmission for each phonon mode depend on the symmetry. These findings suggest that the local heating in the defective nanotubes may be contributed mainly from the low group velocity acoustic phonons and optical phonons near the $\Gamma$-point.