Cooling a material into a ferromagnetic phase can produce arbitrary metastable patterns of magnetic domains rather than a spatially uniform magnetic state. Control over the formation of these patterns could provide non-chemical methods of creating spintronic devices. Here we demonstrate high-efficiency optical training of magnetic domain formation in the two-dimensional van der Waals magnet Fe₃GeTe₂ during zero-field cooling. At ultralow power densities of around 20 µW µm⁻², electrons excited by linearly polarized photons catalyse the formation of larger domains for both spin orientations. Furthermore, circularly polarized photons of the same low power density produce a single domain with its magnetization orientation determined by the optical helicity. We propose that the emergence of this single domain is caused by the optically injected spin-polarized electrons acting as initial magnetic seeds that guide different regions of the sample into the same spin orientation. Our work presents an unconventional route to tailoring spin textures in two-dimensional materials.

将材料冷却到铁磁相中可以产生任意的亚稳态磁畴模式，而不是空间均匀的磁态。控制这些模式的形成可以提供创建自旋电子器件的非化学方法。在这里，我们展示了在零场冷却期间二维范德华磁体 Fe₃GeTe₂ 中磁畴形成的高效光学训练。在大约 20 μW ^μm-2 的超低功率密度下，由线极化光子激发的电子催化形成两个自旋方向的更大畴。此外，具有相同低功率密度的圆偏振光子会产生一个磁化方向由光学螺旋度决定的单个磁化方向。我们提出，这个单畴的出现是由光注入的自旋极化电子引起的，这些电子充当初始磁种子，将样品的不同区域引导到相同的自旋方向。我们的工作提出了一种在二维材料中定制旋转纹理的非常规路线。