  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.
