Field-free spin-orbit torque switching of synthetic antiferromagnet through interlayer Dzyaloshinskii-Moriya interactions
Zilu Wang, Pingzhi Li, Mouad Fattouhi, Yuxuan Yao, Youri L. W. van Hees, Casper F. Schippers, Xueying Zhang, Reinoud Lavrijsen, Felipe García‐Sánchez, E. Martı́nez, A. Fert, Weisheng Zhao, B. Koopmans
Abstract
Perpendicular synthetic antiferromagnets (p-SAFs) are of interest for the next generation of ultrafast, high-density spintronic memory and logic devices. However, to efficiently operate their magnetic order by current-induced spin-orbit torques (SOTs), an unfavored high external magnetic field is conventionally required to break the symmetry. Here, we report the field-free SOT switching of a p-SAF through the introduction of an interlayer with Dzyaloshinskii-Moriya interactions (DMIs). We experimentally observe the existence of the DMI interlayer in our SAF sample by an azimuthal angular-dependent anomalous Hall measurement. Deterministic field-free switching is accomplished in such a sample and depicted by macrospin and micromagnetic simulations. The comparison between the uniaxial interlayer DMI and the azimuthal direction-dependent switching behavior strongly suggests its origin from the DMI interlayer. We demonstrate the compatibility of the proposed strategy with magnetic tunnel junction device structure. Our results provide a strategy for p-SAF-based high-performance SOT devices.