Empirical potential study of phonon transport in graphitic ribbon

TL;DR

This study uses empirical potentials to analyze phonon transport in graphitic ribbons, confirming the potential's reliability and revealing edge-phonon states and quantized thermal conductance features.

Contribution

It demonstrates the effectiveness of Brenner's empirical potential for thermal property analysis and uncovers edge-phonon states and quantized conductance in graphitic ribbons.

Findings

Edge-phonon states are highly localized at ribbon edges.

Low-temperature thermal conductance shows quantization.

Quantization plateau width is inversely proportional to ribbon width.

Abstract

The thermal properties of graphitic ribbon are investigated based on Brenner's empirical potential. The reliability and usefulness of the empirical potential to address the thermal properties of covalent-bonded carbon nanostructures are verified through a comparison of phonon dispersion relations and the density of states of carbon nanotubes with first-principles calculations. The analysis reveals unique edge-phonon states that are highly localized at edge carbon atoms of both armchair and zigzag ribbons. Applying the phonon dispersion relations to the Landauer formula of phonon transport, the quantization and universal features of the low-temperature thermal conductance of graphitic ribbon are elucidated, and it is found that the width of the quantization plateau in the low-temperature region is inversely proportional to the ribbon width.