Spin transport and spin torque in a magnetic nanowire with a non-collinear magnetic order

Abstract

A theory is developed for the treatment of magneto transport properties and spin dynamics in magnetic nanowire that contains a domain wall (DW), i.e. a region of non-collinearity. The method is applicable when the wavelength of spin up and down electrons are larger than the DW width in which case the problem is solvable exactly as a spin-resolved scattering from a strongly localized spin-dependent effective potential created by DW. We present calculations for the current-induced spin density, the distribution of the spin currents, and the spin torque acting locally on the magnetic moments within DW. We also discuss an extension based on the weak gradient (adiabatic) perturbation arising after a local transformation to a uniform magnetization.