激光诱导的磁性手性与纹理依赖的纳米尺度随机域切换研究
Laser-induced helicity and texture-dependent switching of nanoscale stochastic domains in a ferromagnetic film
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中文总结 AI 辅助
本研究通过激光诱导磁性纹理的随机域切换，揭示了手性和纹理对纳米尺度磁性调控的影响。
中文摘要 AI 辅助
在更小的长度和时间尺度上控制磁性纹理是关键的基础和科技问题。实现纳米尺度控制通常依赖于找到能够作用于这些小尺度的外部刺激，这极具挑战性。一个有前途的替代方法是利用磁性纹理本身的不均匀性来实现纳米尺度控制。使用多层铁磁Pt/Co/Pt薄 films结构作为模型系统，我们利用磁力显微镜研究了圆偏振飞秒激光脉冲诱导的磁性纳米纹理变化。从饱和磁态开始，我们发现复杂纳米纹理域网络的随机成核。特别是，这些域的增长不仅取决于其宏观磁化方向，还取决于域纹理的复杂性。这种手性与纹理依赖效应与通常由圆偏振激光脉冲的有效磁场引起的典型均匀域生长形成对比。我们通过一个随机模型验证了我们的发现，其中域的成核和湮灭概率不仅取决于光的手性，还取决于相邻域的相对磁化方向。我们的结果建立了一种新的方法，用于研究超快纳米尺度磁性及跨一级相变的光激发。
英文摘要
Controlling magnetic textures at ever smaller length and time scales is of key fundamental and technological interest. Achieving nanoscale control often relies on finding an external stimulus that is able to act on that small length scales, which is highly challenging. A promising alternative is to achieve nanoscale control using the inhomogeneity of the magnetic texture itself. Using a multilayered ferromagnetic Pt/Co/Pt thin-film structure as a model system, we employ a magnetic force microscope to investigate the change in magnetic nanotextures induced by circularly polarized picosecond laser pulses. Starting from a saturated magnetic state, we find stochastic nucleation of complex nanotextured domain networks. In particular, the growth of these domains depends not only on their macroscopic magnetization but also on the complexity of the domain texture. This helicity and texture-dependent effect contrasts with the typical homogeneous growth of magnetic domains initiated by an effective magnetic field of a circularly polarized laser pulse. We corroborate our findings with a stochastic model for the nucleation of magnetic domains, in which the nucleation and annihilation probability not only depends on the helicity of light but also on the relative magnetization orientation of neighboring domains. Our results establish a new approach to investigate ultrafast nanoscale magnetism and photo-excitation across first-order phase transitions.
