Transport suppression in polymer-doped zigzag carbon nanotubes

The conductance of zigzag carbon nanotubes in the presence of grafted polymers attached to their walls is investigated. A theoretical study of the dependence of the transport on the nature of the molecule and on the concentration of attached structures is presented. The attached structures are shown to lead to the formation of resonant states trapping the electronic carriers and suppressing the conductance. An exponential decay of the conductance with increasing concentration of attached molecules marks the ballistic regime while a weaker decay dependence highlights a crossover to a diffusivelike electronic behavior.