近日，复旦大学吴施伟团队研究了Stoner-Wohlfarth反铁磁体的类铁磁体二进制开关。相关论文于2026年1月28日发表在《自然》杂志上。

斯通纳-沃尔法特反铁磁体是经典斯通纳-沃尔法特模型的延伸（该模型最初用于描述铁磁纳米颗粒的磁化翻转），特指奈尔矢量可通过磁场实现相干翻转的单畴反铁磁体。这类反铁磁体不仅保留了反铁磁性的固有优势，还具有可控的奈尔矢量与完美的开关比特性，因而成为超高密度磁存储器与高算力计算系统的理想构建单元。然而，由于奈尔矢量难以翻转且不可避免地存在多畴结构，块体反铁磁体并不具备斯通纳-沃尔法特反铁磁体的特性。

研究组报道了二维范德瓦耳斯A型反铁磁体CrPS₄展现出理想的斯通纳-沃尔法特反铁磁体特征，这归因于其反铁磁交换作用对磁各向异性的主导地位以及高质量的范德瓦耳斯界面。该材料的反铁磁序在外磁场作用下呈现类铁磁体的二进制式翻转行为，而非其他二维A型反铁磁体中观察到的逐层翻转模式。此外，研究组推导了若干范德瓦耳斯A型反铁磁体的特征交换长度，并提出了判定斯通纳-沃尔法特反铁磁体的标准。该工作由此建立了理解层状反铁磁体磁化翻转的通用框架，并推动了二维反铁磁体在先进自旋电子器件中的有效应用。

附：英文原文

Title: Ferromagnet-like binary switching of a Stoner–Wohlfarth antiferromagnet

Author: Wang, Zhanshan, Xiang, Yining, Chen, Ruohan, Sun, Zeyuan, Hong, Canyu, Chen, Xinyu, Gao, Jingjing, Wu, Shuang, Guo, Zhongxun, Chen, Yi, Mi, Qixi, Liu, Zhongkai, Yan, Shaohua, Lei, Hechang, Ruan, Wei, Zhang, Yuanbo, Yu, Weichao, Liu, Wei-Tao, Yuan, Zhe, Wu, Shiwei

Issue&Volume: 2026-01-28

Abstract: The Stoner–Wohlfarth antiferromagnet (AFM), an extension of the classical Stoner–Wohlfarth model originally describing the magnetization reversal in ferromagnetic nanoparticles1,2, refers to a single-domain AFM whose Néel vector can be coherently switched by the magnetic field. These AFMs not only retain the inherent advantages of antiferromagnetism but also feature controllable Néel vector and a perfect switching ratio, thus emerging as promising building blocks for ultradense magnetic memories and high-throughput computing systems3,4. However, bulk AFMs are not the Stoner–Wohlfarth AFMs owing to the hard-to-switch Néel vector and inevitable multidomain structure3,5,6,7. Here we report that CrPS4, a two-dimensional (2D) van der Waals (vdW) A-type AFM, exhibits ideal characteristics of the Stoner–Wohlfarth AFMs, because of the dominance of antiferromagnetic exchange over the magnetic anisotropy and high quality of vdW interfaces. The antiferromagnetic order undergoes a ferromagnet (FM)-like binary switching with the magnetic field rather than the layer-by-layer flipping observed in other 2D A-type AFMs. Moreover, we deduce the characteristic exchange length of several vdW A-type AFMs and propose a criterion for judging the Stoner–Wohlfarth AFMs. Our work therefore establishes a universal framework for understanding the magnetization reversal in layered AFMs and promotes the effective use of 2D AFMs in advanced spintronic devices.

DOI: 10.1038/s41586-025-10019-9

Source: https://www.nature.com/articles/s41586-025-10019-9