论文标题
在具有不同时间尺度的古典旋转系统中出现拓扑自旋扭矩
Topological spin torque emerging in classical-spin systems with different time scales
论文作者
论文摘要
在具有两个很大不同固有时间尺度的经典自旋系统中，快速旋转的配置几乎瞬间遵循慢速动力学。我们开发了慢速自由度的新兴有效理论，并证明这通常包括拓扑旋转扭矩。这种扭矩引起了异常的实时动力学。它源自定义快速旋转构型空间的自动限制，并根据拓扑电荷密度给出，该密度在整合时变成了量化的同型不变性。
In classical spin systems with two largely different inherent time scales, the configuration of the fast spins almost instantaneously follows the slow-spin dynamics. We develop the emergent effective theory for the slow-spin degrees of freedom and demonstrate that this generally includes a topological spin torque. This torque gives rise to anomalous real-time dynamics. It derives from the holonomic constraints defining the fast-spin configuration space and is given in terms of a topological charge density which becomes a quantized homotopy invariant when integrated.
