A study of the electron properties of ionized carbon nanotubes using the Hubbard model

The electron properties of ionized carbon nanotubes (CNTs) of chirality (5, 5) consisting of 60 atoms have been studied using the Hubbard model. In the context of this consideration, it is possible to explain the coalescence of CNTs and, hence, the formation of aggregates as a result of the charge redistribution between the tubes. The energy of this type of bond per micrometer of tube length turned out to be about 0.1 eV per atom, or about 1.6 keV per micrometer. This result is in qualitative agreement with experiment. The most important and interesting finding is that the excess charge in ionized CNTs is distributed nonuniformly along their length, its density showing maxima and minima.