Independent switching of interfacial exchange bias via antiferromagnet-mediated spin-orbit torque

Electrical control of exchange bias in spintronic heterostructures typically relies on magnetic field cooling, ferromagnet reversal, or metallic antiferromagnets. Here, we report the simultaneous electrical switching of exchange bias and longitudinal resistance via pulse currents in a Pt/NiO/NiFe heterostructure. The switching direction of interfacial pinned spins is independent of the NiFe layer’s magnetization, contrasting with ferromagnet-governed scenarios. By systematically excluding thermal and Oersted-field effects, we attribute this behavior to the reversal of interfacial pinned spins driven by spin-orbit torque mediated through the antiferromagnetic insulator NiO. Supported by spin Hall magnetoresistance measurements and macro-spin simulations, these results demonstrate an insulator-mediated switching mechanism that operates without ferromagnet reversal or charge transport through the antiferromagnet. This work provides a platform for investigating interfacial spin dynamics in antiferromagnetic insulator-based heterostructures.