Sample-specific and Ensemble-averaged Magnetoconductance of Individual Single-Wall Carbon Nanotubes

TL;DR

This study investigates magnetoconductance in individual single-wall carbon nanotubes, revealing both sample-specific and ensemble-averaged effects that diminish with temperature, akin to mesoscopic wire behavior.

Contribution

It provides the first detailed analysis of magnetoconductance contributions in single-wall carbon nanotubes, linking experimental observations to mesoscopic physics concepts.

Findings

Large magnetoconductance of order e^2/h at low temperature

Magnetoconductance has sample-specific and ensemble-averaged components

Both components decrease with increasing temperature

Abstract

We discuss magnetotransport measurements on individual single-wall carbon nanotubes with low contact resistance, performed as a function of temperature and gate voltage. We find that the application of a magnetic field perpendicular to the tube axis results in a large magnetoconductance of the order of e^2/h at low temperature. We demonstrate that this magnetoconductance consists of a sample-specific and of an ensemble-averaged contribution, both of which decrease with increasing temperature. The observed behavior resembles very closely the behavior of more conventional multi-channel mesoscopic wires, exhibiting universal conductance fluctuations and weak localization. A theoretical analysis of our experiments will enable to reach a deeper understanding of phase-coherent one-dimensional electronic motion in SWNTs.