I.-M. Miron, T. Moore, P.-J. Zermatten, G. Serret, S. Auffret, B. Rodmacq, G. Gaudin, A. Schuhl
Controlling locally the motion of magnetic domain walls (DW) by a spin polarized current would lead to new applications in spintronics devices. Up to now, it has been mainly studied in materials with in-plane magnetization. However the diffi- culty of achieving fast and controllable DW motion in such materials has limited the realization of new devices. Moreover, underlying physical mechanisms are still controversial. Micromagnetic simulations have shown that these problems may be overcome in materials with perpendicular anisotropy. We have performed the first direct measurement of the spin transfer torque (STT) efficiency and evidenced a new parameter that can increase this efficiency by two orders of magni- tude.