High efficient field-free magnetization switching via exchange bias effect induced by antiferromagnetic insulator interface

Abstract

Spin–orbit torque induced deterministic magnetization switching typically requires the assistance of an external magnetic field for symmetry breaking. However, achieving field-free switching in perpendicular magnetized layers is crucial for expanding the market of high-density memory. Previous reports have utilized exchange bias, an antiferromagnetic interfacial effect, to realize field-free magnetization switching. However, metallic antiferromagnetic layers will introduce shunting effects that reduce switching efficiency and the Néel vector becomes unstable when current flows through the antiferromagnetic layer. In this study, we achieved the zero-field magnetization switching in NiO/Pt/Co/Pt multilayers. Simulation results demonstrate higher efficiency compared to metallic antiferromagnetic IrMn-based structures. Our findings highlight that the insulator antiferromagnetic can provide an exchange bias field, eliminating the need for an external magnetic field. By avoiding shunting effects, our designed structure offers a more efficient approach for spintronic devices.