Interaction between spin–orbit torque and domain walls in a Ta/MnGa/NiAl structure

We investigate the interaction between spin–orbit torque (SOT) and domain walls (DWs) created during magnetization reversal in perpendicularly magnetized ultrathin MnGa sandwiched between Ta and NiAl. We examine the out-of-plane hysteresis loops under various in-plane magnetic fields H x s along the current I direction by using magnetotransport measurements. The applied I acts as an effective perpendicular magnetic field H eff on magnetization under H x . The slope of H eff versus I varies proportionally to H x and becomes saturated above ~0.15 T, which is consistent with a model based on magnetization reversal through SOT-assisted chiral DW motion under H x .