Field-Free Switching of Perpendicular Magnetization Through Spin Hall and Anomalous Hall Effects in Ferromagnet–Heavy-Metal–Ferromagnet Structures

Abstract

Spin-orbit coupling gives rise to the spin Hall effect (SHE) in nonmagnetic heavy metals, and to the anomalous Hall effect (AHE) in ferromagnetic metals. This article proposes a mechanism to switch the perpendicular magnetization in a magnetic trilayer, without an assisting magnetic field, by utilizing the SHE or AHE plus out-of-plane spin polarization. The authors derive the analytic expression for the resulting spin torque, and perform macrospin simulation to validate the field-free switching. The proposed switching mechanism combines well-established spin-valve technology with the spin Hall effect, potentially enhancing switching efficiency in practical devices.