Electronic states and quantum transport in double-wall carbon nanotubes

TL;DR

This paper systematically investigates electronic states and quantum transport in double-wall carbon nanotubes, revealing how intertube interactions influence conductance and lead to phenomena like conductance quantization and antiresonance effects.

Contribution

It provides new insights into how intertube transfer and energy level separation affect conductance in double-wall carbon nanotubes, especially in incommensurate configurations.

Findings

Bulk scattering is negligible in these nanotubes.

Intertube transfer effects vary depending on energy region and tube commensurability.

Antiresonance with edge states can cause anomalous conductance quantization.

Abstract

Electronic states and transport properties of double-wall carbon nanotubes without impurities are studied in a systematic manner. It is revealed that scattering in the bulk is negligible and the number of channels determines the average conductance. In the case of general incommensurate tubes, separation of degenerated energy levels due to intertube transfer is suppressed in the energy region higher than the Fermi energy but not in the energy region lower than that. Accordingly, in the former case, there are few effects of intertube transfer on the conductance, while in the latter case, separation of degenerated energy levels leads to large reduction of the conductance. It is also found that in some cases antiresonance with edge states in inner tubes causes an anomalous conductance quantization, $G=e^2/\pi\hbar$, near the Fermi energy.