Electrical readout of the antiferromagnetic state of IrMn through anomalous Hall effect

We report the electrical detection of the antiferromagnetic state of IrMn through anomalous Hall measurements in Ta/IrMn heterostructures. The magnetic state is set in the antiferromagnet through field cooling and detected electrically by transverse resistance measurements in Hall bar structures without the need for any ferromagnetic layer. The amplitude of the signal increases with the magnetic field applied during the cooling and is enhanced by the proximal interface with a Ta layer. From the temperature dependence of the effect and the comparison between Ta/IrMn and Ru/IrMn interfaces, we propose an explanation of such readouts based on the simultaneous occurrence of spin-Hall magnetoresistance and magnetic proximity in Ta. These findings highlight how interface effects could be generally employed for the investigation of antiferromagnetic materials as well as for the electrical readout of the antiferromagnetic state.