Tight-binding approach to electronic structure of carbon nanotubes

Abstract

The electronic structure and optical properties of single-wall carbon nanotubes (SWCN's) have been studied using a nearest-neighbor empirical tight-binding model. Hybridization of the σ, π, π* and σ* states of the graphene network is shown to be as important as zone-folding effects in determining the metallicity of small radius carbon nanotubes. The energy dispersion relations are further used to calculate the imaginary part of the dielectric function, which can be directly related to the experimental absorption spectrum