“有趣而无用”的反铁磁材料有望“可读可写”

Core Viewpoint - Fudan University's physics research team has developed a multimodal magneto-optical microscopy technology that reveals a special class of low-dimensional antiferromagnetic systems capable of exhibiting deterministic bistable switching under an external magnetic field, marking a significant advancement in the understanding of antiferromagnetic materials and their potential applications in next-generation low-power, high-speed computing chips [1][2]. Group 1 - The research demonstrates that antiferromagnetic materials, traditionally viewed as less useful compared to ferromagnetic materials, can actually facilitate the development of higher density and faster magnetic storage devices, provided that all magnetic layers can undergo collective bistable switching while maintaining the antiferromagnetic state [1][2]. - The team successfully captured the phenomenon of collective switching in the interlayer antiferromagnet CrPS4, utilizing a self-developed helium-free multimodal magneto-optical system combined with nonlinear optical second harmonic generation technology [2]. - The theoretical framework for the observed experimental phenomena was provided by a team at Fudan University, which conducted micromagnetic simulations to replicate the two types of magnetic switching behaviors observed in experiments [2]. Group 2 - The research introduces the Stoner-Wohlfarth antiferromagnetic model and derives the "characteristic exchange size" to serve as a criterion for the two types of switching behaviors, offering a theoretical guide for the future design and search for antiferromagnetic materials with ideal switching characteristics [2]. - This study represents a transformative breakthrough in the fundamental research of antiferromagnetic dynamics and technical applications, paving the way for the integration of low-dimensional magnetic materials into spintronics and optoelectronics [2].