Electronic structure of carbon nanohorns near the Fermi level

The effect of pentagonal defects on the electronic structure at the tip of the carbon nanohorns is investigated within the continuum gauge field-theory model. It is found that the existence of a localized electron state at the Fermi level (a true zero-mode state) results in the enhanced charge density near the tip. Using a self-consistent perturbation scheme, the eigenfunctions and the local density of states near the pentagonal defects are numerically calculated.