We study large-amplitude oscillations of carbon nanotubes with chiralities (m,0) and (m,m) and predict the existence of localized nonlinear modes in the form of {\em discrete breathers}. In nanotubes with the index (m,0) {\em three types} of localized modes can exist, namely longitudinal, radial, and twisting breathers; however only the twisting breathers, or {\em twistons}, are nonradiating nonlinear modes which exist in the frequency gaps of the linear spectrum. Geometry of carbon nanotubes with the index (m,m) allows only the existence of broad radial breathers in a narrow spectral range.
@article{arxiv.0705.4482,
title = {Discrete Nonlinear Breathing Modes in Carbon Nanotubes},
author = {Alexander V. Savin and Yuri S. Kivshar},
journal= {arXiv preprint arXiv:0705.4482},
year = {2007}
}