By means of {\it ab initio} simulations, we investigate the phonon band structure and electron-phonon coupling in small 4-\AA diameter nanotubes. We show that both the C(5,0) and C(3,3) tubes undergo above room temperature a Peierls transition mediated by an acoustical long-wavelength and an optical q=2kF phonons respectively. In the armchair geometry, we verify that the electron-phonon coupling parameter λ originates mainly from phonons at q=2kF and is strongly enhanced when the diameter decreases. These results question the origin of superconductivity in small diameter nanotubes.
@article{arxiv.cond-mat/0501113,
title = {Room temperature Peierls distortion in small radius nanotubes},
author = {D. Connetable and G. -M. Rignanese and J. -C. Charlier and Xavier Blase},
journal= {arXiv preprint arXiv:cond-mat/0501113},
year = {2009}
}