  Charge resistance and spin torque are generated by coherent carrier transport
through ferromagnetic 360 degree domain walls, although they follow
qualitatively different trends than for 180 degree domain walls. The charge
resistance of 360 degree domain walls reaches a maximum at an intermediate wall
thickness, unlike 180 degree domain walls, whose resistance decreases
monotonically with wall thickness. The peak amplitude of the spin torque and
the optimal thickness of the domain wall to maximize torque for a 360 degree
wall are more than twice as large as found for a 180 degree domain wall in the
same material, producing a larger domain wall velocity for the 360 degree wall
and suggesting unexpected nonlinearities in magnetoelectronic devices
incorporating domain wall motion.
