The effects of impurities and local structural defects upon the conductance of metallic carbon nanotubes were calculated using an ab initio pseudopotential method within the Landauer formalism. Substitutionally-doped boron or nitrogen produced quasi-bound impurity states of definite parity and reduced the conductance by a quantum unit (2e2/h) via resonant back-scattering. These resonant states exhibited a strong similarity to acceptor or donor states in semiconductors. The Stone-Wales defect also produced quasi-bound states and exhibited quantized conductance reduction. In the case of a vacancy, the conductance exhibited a much more complex behavior than predicted by the π-electron tight-binding model.

Defects, Quasibound States, and Quantum Conductance in Metallic Carbon Nanotubes. H.J.Choi, J.Ihm, S.G.Louie, M.L.Cohen: Physical Review Letters, 2000, 84[13], 2917