Hubbard Hamiltonian, high temperature

To describe the electronic structure of carbon nanotubes the Hubbard model has been chosen as it can describe the electrical and magnetic properties and high temperature superconductivity effects also [11]. The model includes the terms of the electron jump energy in vicinity approach and the energy of Coulomb s repulsion of two electrons localized on the same point of unit cell. Hubbard Hamiltonian for the described system is following [11] ... 

Most organic conductors behave as quasi-one-dimensional systems, at least at high temperatures. It is generally accepted that due to the narrow band-widths, the strongest interactions are the electron-electron Coulomb interaction, U for two electrons on the same site, and V for electrons in nearest-neighbor sites, in agreement with the extended Hubbard Hamiltonian, which is usually taken as a good approximation. 

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