  Fully-relativistic first-principles calculations of the Fe(001) surface
demonstrate that resonant surface (interface) states may produce sizeable
tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a
single magnetic electrode. The effect is driven by the spin-orbit coupling. It
shifts the resonant surface band via the Rashba effect when the magnetization
direction changes. We find that spin-flip scattering at the interface is
controlled not only by the strength of the spin-orbit coupling, but depends
strongly on the intrinsic width of the resonant surface states.
