We consider theoretically the spin blockade effect on the spin polarization of a current passing through a geometrically confined head-to-head 180∘ domain wall at a magnetic point contact in a two-dimensional (2D) metallic nanowire. The analysis is based on coherent scattering of the carriers by spin-dependent potential associated with the wall structure. The transmission properties of coherent states are obtained by introducing an algorithm to solve the coupled spin channels Schrödinger equation with mixed Dirichlet–Neumann boundary conditions applied far from the domain wall. It has been shown that a domain wall separating two media of opposite magnetization direction can act as a spin filter, allowing controllable modification of the spin polarization via the wall width.
