Current induced domain wall motion in antiferromagnetically coupled (Co_(70)Fe_(30)/Pd) multilayer nanowires

摘要

We investigate the current induced domain wall (DW) motion in the ultrathin CoFe/Pd multilayer based synthetically antiferromagnetic (SAF) structure nanowires by anomalous Hall effect measurement. The threshold current density (J_(th)) for the DW displacement decreases and the DW velocity (v) increases accordingly with the exchange coupling J_(ex) between the top and bottom ferromagnetic CoFe/Pd multilayers. The lowest J_(th) = 9.3 × 10~(10) A/m~2 and a maximum v = 150m/s with J= 1.5 × 10~(12) A/m~2 are achieved due to the exchange coupling torque (ECT) generated in the SAF structure. The strength of ECT is dependent on both of J_(ex) and the strong spin-orbit torque mainly generated by Ta layer.