标题： 直流驱动畴壁进动区域中的确定性粗糙化 显示英文标题

标题： Deterministic roughening in the dc-driven precessional regime of domain walls

摘要： 我们数值研究了在零温度下由均匀磁场驱动的均匀铁磁体中扩展畴壁的动力学。 使用微磁学Landau-Lifshitz-Gilbert模拟和集体坐标模型，我们表明，当其长度超过一个特征值时，在Walker分解场以上和更高阈值以下，平坦畴壁会变得线性不稳定。 这种不稳定性被一个准普遍的谱图所捕获，该谱图仅由Gilbert阻尼参数化，可预测刚性壁行为的偏差开始。 在线性区域之外，具有不稳定模式带的大畴壁表现出时空混沌、复杂的Bloch线运动和确定性粗糙化。 系统在临界场处经历从平坦移动相到粗糙移动相的动力学相变。 显示英文摘要

摘要： We numerically study the dynamics of extended domain walls in homogeneous ferromagnets driven by a uniform magnetic field at zero temperature. Using both micromagnetic Landau-Lifshitz-Gilbert simulations and a collective-coordinate model, we show that flat domain walls become linearly unstable above the Walker breakdown field and below a higher threshold, provided their length exceeds a characteristic value. This instability is captured by a quasi-universal spectral diagram, parameterized solely by the Gilbert damping, that predicts the onset of deviations from rigid-wall behavior. Beyond the linear regime, large domain walls with bands of unstable modes exhibit spatiotemporal chaos, intricate Bloch line motion, and deterministic roughening. The system undergoes a dynamical phase transition from a flat to a rough moving phase at a critical field.