Field‐Free Spin–Orbit Torque Switching in Perpendicularly Magnetized Synthetic Antiferromagnets
Field‐Free Spin–Orbit Torque Switching in Perpendicularly Magnetized Synthetic Antiferromagnets
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DOI：
10.1002/adfm.202109455
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发表时间：
2021-11
影响因子：
19
通讯作者：
Jinwu Wei;Xiao Wang;B. Cui;C. Guo;Hongjun Xu;Y. Guang;Yuqiang Wang;Xuming Luo;C. Wan;Jiafeng Feng;Hongxiang Wei;G. Yin;Xiufeng Han;G. Yu
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作者：
Jinwu Wei;Xiao Wang;B. Cui;C. Guo;Hongjun Xu;Y. Guang;Yuqiang Wang;Xuming Luo;C. Wan;Jiafeng Feng;Hongxiang Wei;G. Yin;Xiufeng Han;G. Yu
通过铁磁层的层间反铁磁交换耦合形成的合成反铁磁体（SAF）由于零净磁化强度和高热稳定性，在下一代自旋电子器件中表现出令人着迷的潜力。与传统广泛使用的铁磁体相比，由于抑制了净杂散场，SAF有望显着提高数据密度和稳定性。到目前为止，已经明确SAF的自旋轨道扭矩（SOT）切换需要面内有效磁场来打破反演对称性，从而辅助Landau-Lifshitz动力学。该场可以从外部施加，也可以通过相邻铁磁层给出的交换耦合来实现。这种要求阻碍了 SAF 的应用，因为不能排除净磁化。这里，展示了净磁化强度显着降低的全 SAF 系统的无场 SOT 切换。事实证明，该切换在高达 约 460 K 的范围内具有鲁棒性。这项工作为 SAF 在基于 SOT 的存储设备中的实际应用铺平了道路。
Synthetic antiferromagnets (SAFs), formed through an interlayer antiferromagnetic exchange coupling of ferromagnetic layers, exhibit intriguing potential in next‐generation spintronic devices due to the zero net magnetization and the high thermal stability. Compared to ferromagnets that are conventionally widely employed, SAFs are expected to significantly improve the data density and stability due to the suppression of the net stray field. Thus far, it has been well established that the spin‐orbit torque (SOT) switching of SAF requires an in‐plane effective magnetic field to break inversion symmetry and thereby assist the Landau–Lifshitz dynamics. This field can either be externally applied or achieved through the exchange coupling given by an adjacent ferromagnetic layer. Such requirement hinders the application of SAFs since a net magnetization cannot be ruled out. Here, the field‐free SOT switching of an all‐SAF system with a significantly reduced net magnetization is demonstrated. The switching is demonstrated to be robust up to ≈460 K. This work paves the way for the practical applications of the SAFs in the SOT‐based memory devices.