A single-walled carbon nanotube is a  piece of graphene - a single layer of carbon atoms arranged in a honeycomb lattice - rolled into a hollow cylinder with nano metric

diameter and micrometric length. Nanotubes have attracted a continuously increasing interest of scientists in view of the possibility to study new and previously unexplored

phenomena peculiar to one-dimensional metallic conductors.

In  this talk I shall present a detailed comparison between theoretical predictions on electron scattering processes in metallic single-walled carbon nanotubes with

defects and experimental data obtained by scanning tunneling spectroscopy of nanotubes irradiated with Ar-ions. The theoretical model that I shall present

reproduces the features of the particle-in-a-box-like states observed experimentally. Furthermore, the comparison between theoretical and experimental  local density of states yields clear signatures for inter- and intra-valley electron scattering processes depending on the tube chirality.

For the case of armchair single-walled carbon nanotubes, electron scattering depends on the interplay between tube and defect symmetries.  Particularly, I shall show that the conservation of the pseudo-spin and particle-hole symmetry play a crucial role. These last results pave the way for a possible pseudo-spin filter device.

G. Buchs, DB, et al., Phys. Rev. Lett. 102, 245505(2009)

DB et al., Phys. Rev. B 83, 165439 (2011)

L. Mayrhofer and DB, Phys. Rev. B 84, 115126 (2011)