We evaluated the self-induced spin-orbit torque (SOT) in a single ferromagnetic layer. Spin-torque ferromagnetic resonance (ST-FMR) was measured for the very thin Ni-Fe (permalloy, Py) layers with and without structural inversion symmetry: asymmetric and symmetric Py layers. For both structures, the fieldlike component coming from the Oersted field clearly appeared. On the other hand, the dampinglike component was observed only for asymmetric Py with thickness $\le 3\mathrm{nm}$. This dampinglike torque is attributable to the significant spatial change in the properties of Py. We propose a toy model to analyze the self-induced SOT.

中文翻译：

---

Ni-Fe单层中的自旋轨道扭矩

我们评估了单个铁磁层中的自感应自旋轨道扭矩 (SOT)。测量具有和不具有结构反转对称性的非常薄的 Ni-Fe（坡莫合金，Py）层的自旋扭矩铁磁共振 (ST-FMR)：不对称和对称Py 层。对于这两种结构，来自奥斯特场的场状成分清楚地出现。另一方面，仅对于厚度不对称的 Py 观察到类似阻尼的分量$\le 3\mathrm{纳米}$. 这种类似阻尼的扭矩归因于 Py 性质的显着空间变化。我们提出了一个玩具模型来分析自诱导 SOT。