近日，美国马里兰大学Gong, Cheng团队提出了流动二维磁体的高效光学训练。相关论文于2025年6月4日发表在《自然—物理学》杂志上。
将材料冷却成铁磁相可以产生任意亚稳态的磁畴图案，而不是空间均匀的磁状态。对这些图案形成的控制可以提供制造自旋电子器件的非化学方法。研究组演示了在零场冷却过程中二维范德华磁体Fe3GeTe2中磁畴形成的高效光学训练。
在约20 µW μm−2的超低功率密度下 ，由线性偏振光子激发的电子催化了两种自旋取向的更大畴的形成。此外，具有相同低功率密度的圆偏振光子产生单个畴，其磁化方向由光学螺旋度决定。研究组提出，这个单畴的出现是由光学注入的自旋极化电子作为初始磁性种子引起的，这些电子将样品的不同区域引导到相同的自旋方向。该工作提出了一种在二维材料中定制旋转纹理的非传统方法。
附：英文原文
Title: High-efficiency optical training of itinerant two-dimensional magnets
Author: Xie, Ti, Liang, Jierui, Bhattacharya, Dhritiman, Arachchige, Hasitha Suriya, Yakovenko, Victor M., Mandrus, David G., Qiu, Zi Qiang, Liu, Kai, Gong, Cheng
Issue&Volume: 2025-06-04
Abstract: 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 20μWμm2, 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.
DOI: 10.1038/s41567-025-02928-3
Source: https://www.nature.com/articles/s41567-025-02928-3