Beyond the quasi-particle: stochastic domain wall dynamics in soft ferromagnetic nanowires
Beyond the quasi-particle: stochastic domain wall dynamics in soft ferromagnetic nanowires
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DOI：
10.1088/1361-6463/aa553f
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发表时间：
2017-03-01
影响因子：
3.4
通讯作者：
Omari, K. A.
中科院分区：
文献类型：
--
作者：
Hayward, T. J.;Omari, K. A.
我们使用聚焦磁光克尔效应测量和动态微磁模拟来研究软铁磁纳米线中随机畴壁钉扎的物理起源。我们的结果说明了这些效应在 Ni80Fe20 纳米线中普遍存在的性质，并表明它们不仅是系统磁化历史（即注入磁畴壁的磁化结构）和沃克击穿场上方非线性传播动力学的开始的结果，而且是两者之间复杂的相互作用的结果。我们表明，这意味着，虽然微磁学可用于对缺陷位点磁畴壁的行为进行定性预测，但进行定量预测更具挑战性。总之，我们的结果强化了这样的观点：即使在这些简单的伪一维纳米磁体中，磁畴壁也必须被视为复杂的、动态演化的物体，而不是简单的准粒子。
We study the physical origins of stochastic domain wall pinning in soft ferromagnetic nanowires using focused magneto-optic Kerr effect measurements and dynamic micromagnetic simulations. Our results illustrate the ubiquitous nature of these effects in Ni80Fe20 nanowires, and show that they are not only a result of the magnetisation history of the system (i.e. the magnetisation structure of the injected domain walls), and the onset of nonlinear propagation dynamics above the Walker breakdown field, but also a complex interplay between the two. We show that this means that, while micromagnetics can be used to make qualitative predictions of the behaviour of domain walls at defect sites, making quantitative predictions is much more challenging. Together, our results reinforce the view that even in these simple pseudo-one dimensional nanomagnets, domain walls must be considered as complex, dynamically evolving objects rather than simple quasi-particles.