Experimental observation of interfacial Rashba-Edelstein magnetoresistance in Cr/YIG heterostructures

Interfacial Rashba-type spin-orbit coupling is an attractive effect to provide spin-orbit torques without the presence of heavy metals. In this work, we report the experimental observation of the Rashba-Edelstein magnetoresistance in the Cr/YIG heterostructure, which can indicate the presence of the interfacial spin-orbit coupling. By comparing the angular-dependent magnetoresistance of the Cr/YIG and the Cr/Cu/YIG heterostructures, we identify that the magnetoresistance in the Cr/YIG heterostructure is superimposed with two parts: the Rashba-Edelstein magnetoresistance induced by the interfacial spin-orbit coupling and the anisotropic magnetoresistance induced by the magnetic proximity effect. The Rashba-Edelstein magnetoresistance shows a nonsaturated external field dependence, which can be attributed to the Hanle magnetoresistance and the interfacial antiferromagnetic ordering of the Cr layer. Our findings show an approach to obtain spin-orbit torques via the interfacial spin-orbit coupling for YIG-based devices. Furthermore, our findings also provide an understanding of the multiple couplings at the $3d$-metal/YIG interface.