Field-free spin-orbit torque switching of synthetic antiferromagnet through interlayer interactions

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 or-der by current-induced spin-orbit torques (SOTs), an unfavored high external magnetic field is conventionally required to break the sym-metry. 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 exis-tence 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 be-tween 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 pro-posed strategy with magnetic tunnel junction device structure. Our results provide a strategy for p-SAF-based high-performance SOT devices.

Automated summary

Field-free spin-orbit torque (SOT) switching of perpendicular synthetic antiferromagnets (p-SAFs) is achieved through the introduction of an interlayer with Dzyaloshinskii-Moriya interactions (DMIs). The existence of the DMI interlayer is experimentally confirmed, and deterministic field-free switching is demonstrated. The proposed strategy is compatible with magnetic tunnel junction device structure and provides a method for high-performance SOT devices based on p-SAFs.