Fractional quantum conductance in carbon nanotubes

Using a scattering technique based on a parametrized linear combination of atomic orbitals Hamiltonian, we calculate the ballistic quantum conductance of multi-wall carbon nanotubes. We find that inter-wall interactions not only block some of the quantum conductance channels, but also redistribute the current non-uniformly over the individual tubes across the structure. Our results provide a natural explanation for the unexpected integer and non-integer conductance values reported for multi-wall nanotubes in Ref.[S. Frank, P. Poncharal, Z.L. Wang, and W. A. de Heer, Science 280, 1744 (1998)]