Electronic Structure and Quantum Conductance of Carbon Nanotubes

Abstract

The unique electronic properties of carbon nanotubes stem from the fact that the electronic structure of these systems is derived from a folded graphene band structure which is highly sensitive to the tube diameter and chirality. In this chapter, we review some theoretical work on the electronic and transport properties of the single-walled carbon nanotubes, including systems with junction structures, defects, and disorder. On-tube metal-metal, semiconductor-semiconductor, and metalsemiconductor junctions have been studied. In addition, substitutional impurities and pentagon-heptagon defect pairs are shown to have interesting effects on the conductance. The structure and properties of crossed nanotube junctions and disordered nanotubes with static external perturbations have also been studied. The nanoscale size and the unique electronic properties of the carbon nanotubes make the potential usage of these novel systems for new device applications very promising.