Doping state of multi-wall carbon nanotubes wires and quantum dots
Abstract
Employing strong electrostatic gating (liquid-ion gating), the position of the Fermi energy E_F (relative to the charge-neutrality point) was determined in multi-wall carbon nanotubes (MWNTs). E_F is negative (hole doping) and amounts to \approx -0.3 eV for MWNTs in air. Evidence that water, and not oxygen, is the main source of doping has been found. As a consequence, the number M of occupied 1d-modes (not counting spin) is >2, i.e. M \approx 10. This is supported by the single-electron level spacing, deduced from observed single-electron charging effects (SET) at low temperature. The latter are dominated by co-tunneling processes, as we observe the Kondo effect. This provides evidence, that highly transmissive channels are present in MWNTs at low temperature, despite the `disorder' observed in previous experiments.
Keywords
Cite
@article{arxiv.cond-mat/0106501,
title = {Doping state of multi-wall carbon nanotubes wires and quantum dots},
author = {Christian Schönenberger and Mark Buitelaar and Michael Krüger and Isabelle Widmer and Thomas Nussbaumer and Mahdi Iqbal},
journal= {arXiv preprint arXiv:cond-mat/0106501},
year = {2007}
}
Comments
Proceedings Moriond 2001, 6 pages, 4 figures