Band structure modulation in carbon nanotube-metal junction

In transport experiments carbon nanotubes (NTs) are embedded in metallic contacts. Distortion of NT shape within the NT-metal junction region may result in the change of NT electronic structure: the deformation can open a band gap in otherwise metallic nanotube, and reduce or completely close the gap in a semiconducting one. Local band structure modulation has non-negligible effect on the electron transmission through NT-metal interface, e.g. the Shottky barrier transparency is changing exponentially with the gap width. To analyze the deformation-induced change of the NT band structure in the contact region, we develop a comprehensive theory of the inhomogeneous deformations in NT, which combines the tight-binding approach with continuous description of the deformation field, and is applicable for NT of any chirality. We calculate the band gap variation in the contact region, and discuss the effect of the deformation on the NT-metal contact resistance.