Real-time analysis of the spinmotive force due to domain wall motion

Using numerical simulations, we study the spinmotive force induced by domain wall motion in a high magnetic field region far above the Walker breakdown field. We find that the DC component of the spinmotive force scales with the applied magnetic field even in a field range where the wall motion is no longer associated with periodic angular rotation of the wall magnetization. As the field is increased, spikes in the voltage signals start to appear, which are mainly attributed to vortex core collisions, nucleation, and annihilation, and this tendency is enhanced with further increases in the field. At high fields, the slope of the generated DC voltage vs. applied field curve is expected to depend only on the spin polarization of conduction electrons and, thus, can be used to accurately determine the degree of spin polarization in various materials.