Electrical transport in doped multiwalled carbon nanotubes - art. no. 161404

The effects of doping, electron coherence, and electron correlation on the transport properties of boron-doped multiwalled carbon nanotubes are studie d. Substitutional boron lowers the Fermi level of the tubes and increases t he number of participating conduction channels without introducing strong c arrier scattering. From 300 to about 50 K, the tubes show metallic behavior with weak electron-phonon coupling. At lower temperatures the resistance i ncreases, and a zero-bias anomaly is observed. The magnetoresistance is now negative indicating the importance of coherent back-scattering processes. The coherence lengths are measured and dephasing is found to involve weakly inelastic electron-electron collisions. The temperature dependence of the resistance as well as the other low temperature observations can be account ed for by one-dimensional weak-localization theory.