The manipulation of magnetization via magnetic torques is one of the most important phenomena in spintronics. In thin films, conventionally, a charge current flowing in a heavy metal is used to generate transverse spin currents and to exert torques on the magnetization of an adjacent ferromagnetic thin film layer. Here, in contrast to the typically employed heavy metals, we study spin-to-charge conversion in ferromagnetic heterostructures with large spin-orbit interaction that function as the torque-generating layers. In particular, we chose perpendicular magnetic anisotropy (PMA) multilayers [Co/Ni] and [Co/Pt] as the torque-generating layers and drive magnetization dynamics in metallic ferromagnetic thin film ${\mathrm{Co}}_{20}{\mathrm{Fe}}_{60}{\mathrm{B}}_{20}$ (CoFeB) layers with in-plane magnetic anisotropy (IMA). We investigate the spin dynamics driven by spin-orbit torque (SOT) and the concomitant charge current generation by the inverse SOT process using an inductive technique based on a vector network analyzer. In our experimental findings, we find that the SOTs generated by our multilayers are of a magnitude comparable to those produced by Pt, consistent with first-principles calculations. Furthermore, we noted a significant correlation between the SOT and the thickness of the CoFeB layer.

中文翻译：

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磁性异质结构中逆自旋轨道扭矩的感应检测


通过磁力矩操纵磁化是自旋电子学中最重要的现象之一。在薄膜中，传统上，在重金属中流动的充电电流用于产生横向自旋电流并对相邻铁磁薄膜层的磁化施加扭矩。在这里，与通常使用的重金属相反，我们研究了具有大自旋轨道相互作用的铁磁异质结构中的自旋电荷转换，该相互作用充当扭矩产生层。特别是，我们选择垂直磁各向异性（PMA）多层[Co/Ni]和[Co/Pt]作为扭矩产生层并驱动金属铁磁薄膜中的磁化动力学 ${\mathrm{Co}}_{20}{\mathrm{Fe}}_{60}{\mathrm{B}}_{20}$ (CoFeB) 层具有面内磁各向异性 (IMA)。我们使用基于矢量网络分析仪的感应技术研究了自旋轨道扭矩 (SOT) 驱动的自旋动力学以及逆 SOT 过程产生的伴随充电电流。在我们的实验结果中，我们发现多层膜产生的 SOT 的数量级与 Pt 产生的 SOT 相当，这与第一原理计算一致。此外，我们注意到 SOT 和 CoFeB 层的厚度之间存在显着相关性。