FIRST-PRINCIPLES BAND STRUCTURES OF ARMCHAIR NANOTUBES

Recent work by Thess et al. suggests that (10,10) carbon nanotubes wit h diameters of 1.38 nm have been observed with high conductivities. Ot her experimental results have directly measured the density of states of single-wall carbon nanotubes with diameters in the range 1-1.5nm. H erein we examine the expected electronic properties of armchair single -wall nanotubes with diameters in this range, and present first-princi ples local-density functional results for band structure and density o f states of these SWNTs. We find our results support the validity of t he simple graphene sheet model, and are in close agreement with experi mental measurements of the density of states of these materials.