Ferromagnet-like binary switching of a Stoner-Wohlfarth antiferromagnet.

Wang, Zhanshan; Xiang, Yining; Chen, Ruohan; Sun, Zeyuan; Hong, Canyu; Chen, Xinyu; Gao, Jingjing; Wu, Shuang et al. · Nature · 2026

basic_science · Level V

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Abstract

The Stoner-Wohlfarth antiferromagnet (AFM), an extension of the classical Stoner-Wohlfarth model originally describing the magnetization reversal in ferromagnetic nanoparticles<sup>1,2</sup>, 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 systems<sup>3,4</sup>. However, bulk AFMs are not the Stoner-Wohlfarth AFMs owing to the hard-to-switch Néel vector and inevitable multidomain structure<sup>3,5-7</sup>. Here we report that CrPS<sub>4</sub>, 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.