Microwave Transport in Metallic Single-Walled Carbon Nanotubes

TL;DR

This study measures the high-frequency conductance of single-walled carbon nanotubes, showing they can carry ac currents as effectively as dc currents across a broad frequency range, with implications for high-speed electronics.

Contribution

It provides the first experimental measurement of the ac conductance of single-walled carbon nanotubes from dc to 10 GHz, demonstrating their high-frequency transport capabilities.

Findings

Ac conductance equals dc conductance up to 10 GHz.

Nanotubes can carry high-frequency currents effectively.

A phenomenological model explains ac impedance with scattering effects.

Abstract

The dynamical conductance of electrically contacted single-walled carbon nanotubes is measured from dc to 10 GHz as a function of source-drain voltage in both the low-field and high-field limits. The ac conductance of the nanotube itself is found to be equal to the dc conductance over the frequency range studied for tubes in both the ballistic and diffusive limit. This clearly demonstrates that nanotubes can carry high-frequency currents at least as well as dc currents over a wide range of operating conditions. Although a detailed theoretical explanation is still lacking, we present a phenomenological model of the ac impedance of a carbon nanotube in the presence of scattering that is consistent with these results.