Quantum Transport in a Carbon Nanotube in Magnetic Fields

Abstract

The conductance of single-shell carbon nanotubes is numerically calculated in the effective-mass approximation by treating scattering from impurities exactly.The magnetic-field dependence of the conductance depends sensitively on the mean free path.When the mean free path is sufficiently large, undoped metallic nanotubes exhibit a large positive magnetoresistance in agreement with the prediction of the Boltzmann transport equation.This positive magnetoresistance disappears when the mean free path becomes comparable to the circumference length.