title: Spin-dependent scattering by a potential barrier on a nanotube.
abstract: The electron spin effects on the surface of a nanotube have been considered through the spin-orbit interaction (SOI), arising from the electron confinement on the surface of the nanotube. This is of the same nature as the Rashba-Bychkov SOI at a semiconductor heterojunction. We estimate the effect of disorder within a potential barrier on the transmission probability. Using a continuum model, we obtain analytic expressions for the spin-split energy bands for electrons on the surface of nanotubes in the presence of SOI. First we calculate analytically the amplitudes of scattering from a potential barrier located around the axis of the nanotube into spin-dependent states. The effect of disorder on the scattering process is included phenomenologically and induces a reduction in the transition probability. We analyze the relative role of SOI and disorder in the transmission probability which depends on the angular and linear momentum of the incoming particle, and its spin orientation. Finally we demonstrate that in the presence of disorder, perfect transmission may not be achieved for finite barrier heights.
authors.affiliation: Department of Physics and Astronomy, Hunter College at the City University of New York, New York, NY 10065, USA. yabranyo@hunter.cuny.edu
authors.forename: Yonatan
authors.initials: Y
authors.lastname: Abranyos
authors.forename: Godfrey
authors.initials: G
authors.lastname: Gumbs
authors.forename: Paula
authors.initials: P
authors.lastname: Fekete