Europhys. Lett.
Volume 70, Number 2, April 2005
Page(s) 204 - 210
Section Condensed matter: structural, mechanical and thermal properties
Published online 16 March 2005
Europhys. Lett., 70 (2), pp. 204-210 (2005)
DOI: 10.1209/epl/i2004-10482-0

Conductance gap and zero-bias conductance scaling in metallic carbon nanotubes

J. W. Ding1, 2 and D. Y. Xing1

1  National Laboratory of Solid State Microstructures Nanjing University - Nanjing 210093, PRC
2  Department of Physics, Xiangtan University Xiangtan 411105, Hunan, PRC

received 26 November 2004; accepted 28 February 2005
published online 16 March 2005

A new supercell approach is presented to the calculations for quantum conductance of single-wall carbon nanotubes as a function of tube length L, diameter d, and chirality. It is shown that there is a conductance gap (dip) in infinite (finite) metallic non-armchair nanotubes due to the curvature-induced energy gap, while it is absent in armchair tubes. This mediates a dispute in experiments. A scaling of $G=2G_0\exp[-\beta L/d^2]$ is obtained for the zero-bias conductance where G0=2e2/h and $\beta$ depends only on the chiral angle. This behavior can be well understood by a proposed tunneling model.

61.48.+c - Fullerenes and fullerene-related materials.
71.20.Tx - Fullerenes and related materials; intercalation compounds.

© EDP Sciences 2005