The phonon dispersion relations of SW-CNTs can be calculated using zone
folding [29], tight-binding methods[37,38,39,40], density functional theory
[41,42,43,44,45,46,47,48,49],
and symmetry-adapted models [50,51,52,53,54].
The phonon dispersion relations of SW-CNTs can be understood by zone
folding of the phonon dispersion branches of graphene.
Subsections