Spin-Orbit Torque's Hidden Partner
arXiv:2607.26392
The paper demonstrates that the Zhang‑Li spin‑transfer torque, when combined with interfacial Dzyaloshinskii‑Moriya interaction, can induce magnetization switching in heavy‑metal/ferromagnet bilayers in a manner similar to spin‑orbit torque, suggesting it as a complementary switching mechanism for SOT‑MRAM devices.
Abstract
The spin-orbit torque (SOT) is widely recognized as the primary mechanism for current-driven magnetization switching in nonmagnetic/ferromagnetic bilayers. In this work, we show that, in the presence of interfacial Dzyaloshinskii-Moriya interaction (iDMI), the Zhang-Li torque, a current-induced spin-transfer torque (STT) acting on nonuniform magnetization at the device boundary, can trigger switching behaviors strikingly similar to those of SOT, including field-assisted deterministic reversal and switching polarity control. These results suggest that the Zhang-Li torque may act as a significant complementary mechanism to SOT. This work provides a broader perspective on the switching physics in heavy metal/ferromagnet (HM/FM) structures and offers practical guidance for the design of SOT-MRAM devices.
11 pages, 4 figures. Submitted to Physical Review Letters