Current-Driven Magnetization Switching via Zhang-Li Torque

Abstract

Current-driven magnetization switching is currently governed by two established mechanisms: the Slonczewski spin-transfer torque (STT) and the spin-orbit torque (SOT). Here we identify the Zhang-Li STT as a third mechanism that operates on a different physical footing. Using micromagnetic simulations, we show that the interfacial Dzyaloshinskii-Moriya interaction (iDMI) inevitably creates spatial magnetization gradients at device edges, enabling the Zhang-Li torque to drive deterministic, field-assisted switching that fully reproduces all hallmark behaviors of SOT, including polarity control and effective-field characteristics. Our work establishes the Zhang-Li torque as an autonomous switching pathway, redefining the physical picture of current-induced magnetization reversal and providing new design principles for spintronic devices.

7 pages, 4 figures. Revised title, abstract, presentation, discussion, references, and equation numbering; the central physical conclusions remain unchanged