Effects of short-range scatterers on perfect channel in metallic carbon nanotubes

Numerical calculations of the conductance are performed to study effects of short-range scatterers on a perfectly conducting channel in metallic carbon nanotubes existing unless the potential range of scatterers is smaller than the lattice constant. The perfect channel can easily be destroyed in the presence of small amount of short-range scatterers when there are several bands at the energy, while it is much more robust in the energy range of metallic linear bands.