Emergent zero-field anomalous Hall effect in a reconstructedrutileantiferromagnetic metal

Abstract

Anomalous Hall effect (AHE) emerged in antiferromagnetic metals shows intriguing physics and application potential. In contrast to certain noncollinear antiferromagnets, rutile RuO${}_2$ has been proposed recently to exhibit a crystal-assisted AHE with collinear antiferromagnetism. However, in RuO${}_2$, the on-site magnetic moment accompanying itinerant 4d electrons is quite small, and more importantly, the AHE at zero external field is prohibited by symmetry because of the high-symmetry [001] direction of the Néel vector. Here, we show the AHE at zero field in the collinear antiferromagnet, Cr-doped RuO${}_2$. The appropriate doping of Cr at Ru sites results in a rotation of the Néel vector from [001] to [110] and enhancement of the on-site magnetic moment by one order of magnitude while maintaining a metallic state with the collinear antiferromagnetism. The AHE with vanishing net moment in the Ru${}_{0.8}$Cr${}_{0.2}$O${}_2$ exhibits an orientation dependence consistent with the [110]-oriented Néel vector. These results open a new avenue to manipulate AHE in antiferromagnetic metals.