Tamm states of carbon nanotubes

The fine structure of the π-electron spectrum of semi-infinite carbotubulenes (cylindrical graphene tubes) is investigated. Together with closed short-diameter tubelenes, open nanotubes whose terminal fragments contain heteroatoms are studied. Algebraic equations are obtained for the one-electron energy levels corresponding to wave functions localized on a terminal fragment. It is shown that Tamm energy levels, lying in either the band gaps or the continuous spectrum (resonance states), can exist in the systems studied. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 8, 588–593 (25 April 1996)