Current-driven dynamics of coupled domain walls in a synthetic antiferromagnet

We develop the theory of magnetic domain-wall motion in coupled double-layer systems where electrons can hop between the layers, giving rise to an antiferromagnetic coupling. We demonstrate that the force from the interlayer coupling drives the walls and the effect of the extrinsic pinning is greatly reduced if the domain walls are initially separated. The threshold current density for metastable spin-aligned configurations is also much lower. We conclude that the interlayer coupling has a significant effect on domain-wall mobility in double-layer systems.