Fan Yijie, Xu Yihong, Bian Renji, Zhang Ruan, Mei Junning, Wu Jiaxin, Xie Binghe, Zhu Shuangxing, Chen Yu, Gu Feifan, Liu Ying, Taniguchi Takashi, Watanabe Kenji, Liu Fucai, Cai Xinghan
National Key Laboratory of Advanced Micro and Nano Manufacture Technology, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Proc Natl Acad Sci U S A. 2025 Apr 15;122(15):e2414668122. doi: 10.1073/pnas.2414668122. Epub 2025 Apr 8.
Magnetic anisotropy plays a crucial role in determining the critical behavior and phase transitions in two-dimensional magnetic systems. It is also required for the design of thin-film spintronic devices. Despite its significance, sensing extremely weak anisotropy has proven challenging in van der Waals antiferromagnetic/ferrimagnetic materials. Here, we first employ simulations of micromagnetic energy function in few-layer easy-plane antiferromagnetic systems with a weak additional uniaxial anisotropy and unveil an intriguing even-odd effect closely linked to low-field spin-flop behaviors. We further perform tunneling magneto-conductance measurements on a model 2D antiferromagnetic insulator, CrCl, exhibiting near-ideal easy-plane anisotropy. The magnetic field-controlled tunneling current at low temperature aligns well with simulated in-plane anisotropic spin-configuration, providing direct experimental evidence for detecting magnetic anisotropy field around 1 mT. Our work creates opportunities for finely characterizing magnetic structures and behaviors in 2D antiferromagnetic/ferrimagnetic systems, with potential applications in spintronics such as data storage and magnetic sensing.
磁各向异性在确定二维磁系统中的临界行为和相变方面起着至关重要的作用。它也是薄膜自旋电子器件设计所必需的。尽管其具有重要意义，但在范德华反铁磁/亚铁磁材料中，检测极其微弱的各向异性已被证明具有挑战性。在此，我们首先在具有弱附加单轴各向异性的少层易平面反铁磁系统中采用微磁能函数模拟，并揭示了一种与低场自旋翻转行为密切相关的有趣奇偶效应。我们进一步对一种具有近乎理想易平面各向异性的二维反铁磁绝缘体模型CrCl进行了隧穿磁电导测量。低温下磁场控制的隧穿电流与模拟的面内各向异性自旋构型吻合良好，为检测约1 mT的磁各向异性场提供了直接实验证据。我们的工作为精细表征二维反铁磁/亚铁磁系统中的磁结构和行为创造了机会，在数据存储和磁传感等自旋电子学领域具有潜在应用。
