Eur. Phys. J. B 36, 317-326 (2003)
https://doi.org/10.1140/epjb/e2003-00350-9

Selection rules and superconducting correlations in carbon nanotubes

Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain

Corresponding author: ^a imtjg64@pinar2.csic.es

Received: 13 August 2003
Published online: 23 December 2003

Abstract

We carry out a detailed analysis of the effective interaction arising from electron-phonon scattering and its capability to produce the superconducting correlations observed in the carbon nanotubes. It is shown that certain selection rules prevent the exchange of phonons in some of the interaction channels, depending on the geometry of the nanotubes and on whether they are doped or not. In addition, we discuss the mechanism working in nanotube ropes by which the electrostatic coupling among a large number of metallic nanotubes leads to a substantial reduction in the strength of the Coulomb interaction. The scaling equation for the superconducting response function is then improved nonperturbatively, by including the exact contribution from forward-scattering processes. This allows us to estimate the boundary between superconducting and nonsuperconducting phases in the ropes, as well as to constrain the actual values of the strength of the effective attractive interaction.