Current-induced unidirectional magnetoresistance in Pt/FeRh bilayers*

The unidirectional magnetoresistance (UMR) effect has garnered considerable interest since it can provide fundamental insight into the transport properties of spin-orbit coupled systems. The origin of the UMR in ferromagnet and non-magnetic bilayers has been actively studied [1,2] but experimental investigations of the UMR in metallic antiferromagnet and non-magnetic bilayers are lacking.
In this work, we report a UMR effect in the antiferromagnetic phase of a Pt/FeRh bilayer. A smooth evolution of UMR with respect to current density and magnetic field suggests that the UMR can be attributed to the interaction between the current-induced spin accumulation and the canting of the individual spin sublattices in FeRh in response to the in-plane field. Our results suggest a route to manipulate and detect the magnetization states in metallic antiferromagnets.
[1] C. O. Avci et al., Nature Physics 11, 570-575 (2015).
[2] K. Yasuda et al., Phys. Rev. Lett. 117, 127202 (2016).