  Effects of impurity on the spin-dependent transport in a single wall carbon
nanotube spin-valve, as ferromagnetic electrode/carbon nanotube/ferromagnetic
electrode model junction is numerically investigated. Using a generalized
Green's function method and the Landauer-Buttiker formalism, the impurity
conditions are determined by randomly substitution of carbon atoms in the
honeycomb carbon nanotube lattice by nitrogen and boron atoms. We have found
that transport characteristics, including the spin-dependent current and tunnel
magnetoresistance are strongly influenced by the impurity effects. We think
that the results of the present report could be useful for designing the future
spintronic devices.
