Suppression Effect on the Domain Wall Tilting in Synthetic Antiferromagnetic Racetrack Driven by the Spin–Orbit Torque

Abstract

The perpendicularly magnetized synthetic antiferromagnet is an ideal candidate for racetrack memory due to the low stray field, allowing the closely packed domain wall (DW) and high recording density. Herein, the dynamics of DW motion driven by the magnetic field and current are investigated in the synthetic antiferromagnetic (SAF) Ta/Pt/Co/Pt/Ru/Pt/Co/Ta structures with different thicknesses of the top magnetic (TM) Co layers. The results illustrate that the direction of the DW motion will be reversed when the field pulse is below a critical field for the sample with a negligible remanence ratio. As for the current‐driven DW motion case, a significant enhancement of the DW velocity, as well as a strong suppression effect on the tilting of DW's plane due to the strong interlayer exchange coupling for the SAF structure, is found. The fast DW velocity and small tilting angle in SAF are valuable for spintronic racetrack memories.