We present measurements of current-induced spin–orbit torques generated by NbSe₂, a fully metallic transition-metal dichalcogenide material, made using the spin-torque ferromagnetic resonance (ST-FMR) technique with NbSe₂/Permalloy bilayers. In addition to the out-of-plane Oersted torque expected from current flow in the metallic NbSe₂ layer, we also observe an in-plane antidamping torque with torque conductivity σ_S ≈ 10³ (ℏ/2e)(Ωm)⁻¹ and indications of a weak field-like contribution to the out-of-plane torque oriented opposite to the Oersted torque. Furthermore, in some samples we also measure an in-plane field-like torque with the form m̂ × ẑ, where m̂ is the Permalloy magnetization direction and ẑ is perpendicular to the sample plane. The size of this component varies strongly between samples and is not correlated with the NbSe₂ thickness. A torque of this form is not allowed by the bulk symmetries of NbSe₂ but is consistent with symmetry breaking by a uniaxial strain that might result during device fabrication.

中文翻译：

---

NbSe ₂ /坡莫合金双层中的自旋轨道扭矩

我们介绍了由NbSe ₂（一种全金属过渡金属二硫化氢材料）生成的电流感应自旋轨道扭矩的测量结果，该材料是使用NbSe ₂ /坡莫合金双层自旋扭矩铁磁共振（ST-FMR）技术制成的。除了外的平面奥斯特扭矩从在金属NbSe电流流动预期₂层，我们还观察的面内antidamping扭矩与扭矩电导率σ_小号≈10 ³（ℏ/ 2 ë）率（Ωm）^-1并显示出与Oersted扭矩相反方向的平面外扭矩产生的类似场的弱贡献。此外，在某些样本中，我们还测量了形式为m的面内场状转矩̂× z ̂，其中m ̂是坡莫合金的磁化方向，z ̂垂直于样品平面。该组分的大小在样品之间变化很大，并且与NbSe _2的厚度无关。NbSe ₂的整体对称性不允许这种形式的扭矩，但与在设备制造过程中可能会因单轴应变而导致的对称性破坏相一致。