Unidirectional magnetoresistance in an insulating compensated ferrimagnet

We investigate the unidirectional magnetoresistance (UMR) in a GdIG(Gd3Fe5O12)/Pt bilayer. We find a suppression of the observed UMR as the magnetic field increases, suggesting a magnonic origin for the UMR effect. Furthermore, through the examination of the temperature dependence of UMR, we observe that the sign of the UMR remains unchanged at the compensation temperature. This observation indicates that the magnon contributing to the UMR is associated with the lowest magnon mode with a distinct handedness. Our results provide compelling evidence for the existence of magnonic UMR in compensated ferrimagnets, offering potential advantages for spintronic applications.