Carbon nanotubes in the Coulomb blockade regime

Quantum transport through finite-length single wall carbon nanotubes was investigated theoretically in the Coulomb blockade regime. The spin-degenerate state of the nanotube is found to play a crucial role, and is responsible for the experimentally observed alternation in the heights of the conductance spectrum as electrons are added to the nanotubes. We also show that the relaxation of the energy eigenstates, which takes place as the electrons tunnel to and from the nanotubes, is responsible for the current saturation as a function of bias voltage polarity.