Anomalous Hall effect in Mn1.5Ga/Ta and Mn1.5Ga/Pt bilayers: Modification from spin-orbit coupling of heavy metals

We report systematic measurements of anomalous Hall effect (AHE) in Mn1.5Ga/Ta and Mn1.5Ga/Pt bilayers modified by strong spin-orbit coupling (SOC) of the heavy metals. The results are compared with the AHE in Mn1.5Ga/Cu with weak SOC. We have used a scaling involving multiple competing scattering mechanisms to distinguish different contributions to the modified AHE. The scaling analysis reveals that the origin of the modified AHE in Mn1.5Ga/Cu is different from those in Mn1.5Ga/Ta and Mn1.5Ga/Pt. The direct observation of spin-orbit torque induced magnetization switching confirms that the result is a combination of the AHE of Mn1.5Ga and spin Hall effect of the heavy metals.