Electronic Structure of Fullerene Tubules

Recent reports suggest that graphitic tubules with diameters on the order of fullerene diameters have been synthesized. Such small-diameter tubules should have electronic properties related to those of two-dimensional graphite. We demonstrate by comparison with results from a first principles, self-consistent, all electron Gaussian-orbital based local-density functional approach that an all-valence tight binding model can be expected to give a reasonable description of the electronic states of these tubules. In analyzing both high-symmetry tubules and lower-symmetry chiral tubules, we see that a relatively high carrier density could be expected for many of these structures.