We introduce a new extended Heisenberg model that contains orbital-dependent spins together with the retarded effects of spin torque. The model is directly derived from the dynamical linear response functions on the transversal spin fluctuation. Our model allows us to address effects that are not accessible via the usual Heisenberg model. With the model, we can describe not only the relaxation effects due to the Landau damping caused by the Stoner excitations, but also the nesting effects of the Fermi surface. We discuss the possibilities of the extended Heisenberg model on the basis of high-resolution plots of the spin susceptibility for Fe.

中文翻译：

---

自旋动态线性响应的非线性扩展：扩展海森堡模型

我们引入了一个新的扩展海森堡模型，该模型包含轨道相关自旋以及自旋扭矩的延迟效应。该模型直接从横向自旋涨落的动态线性响应函数推导出来。我们的模型允许我们解决通过通常的海森堡模型无法访问的影响。通过该模型，我们不仅可以描述因斯通纳激发引起的朗道阻尼的弛豫效应，还可以描述费米面的嵌套效应。我们在 Fe 的自旋磁化率的高分辨率图的基础上讨论了扩展海森堡模型的可能性。