This paper studies spin–orbit torque (SOT) switching behaviors in synthetic antiferromagnet (SyAF) structures of Ta/[Pt/Co]m/Ru/[Co/Pt]n, which are asymmetric between the upper multilayer (UML) and the bottom multilayer (BML). The SOT-induced magnetization switching loops show multiple transitions of switching orientations between clockwise and anticlockwise with an increasing in-plane magnetic field, determined by the effects of the Dzyaloshinskii–Moriya interaction from both the BML and UML in the different stacking structures. Moreover, the field-free SOT switching was observed in the structure of Ta/[Pt/Co]3/Ru (0.5)/[Co/Pt]4. It can be attributed to the horizontal component of magnetic moments in its UML acting as an equivalent field. Therefore, the SyAF structures could be potential candidates for the future SOT-based spintronic devices.

中文翻译：

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合成反铁磁体中自旋轨道扭矩引起的多重磁化切换行为

本文研究了 Ta/[Pt/Co]m/Ru/[Co/Pt]n 的合成反铁磁体 (SyAF) 结构中的自旋轨道扭矩 (SOT) 切换行为，这些结构在上层 (UML) 和底部多层（BML）。SOT 诱导的磁化切换回路显示出顺时针和逆时针之间切换方向的多次转变，随着面内磁场的增加，这取决于不同堆叠结构中 BML 和 UML 的 Dzyaloshinskii-Moriya 相互作用的影响。此外，在 Ta/[Pt/Co]3/Ru (0.5)/[Co/Pt]4 结构中观察到无场 SOT 切换。它可以归因于作为等效场的 UML 中磁矩的水平分量。因此，SyAF 结构可能是未来基于 SOT 的自旋电子器件的潜在候选者。