Electrical transport in carbon nanotubes: Role of disorder and helical symmetries

For carbon nanotubes, we determine the role of disorder and helicity in the transport length scales and intrinsic conductance. Our results highlight different physical phenomena originating from defect scattering and multishell conduction. Those effects are sensitive to the position of the Fermi level, and allow for a consistent interpretation of recent transport experiments in doped nanotubes.