Gu Pingfan, Peng Yuxuan, Yang Shiqi, Wang Huan, Ye Shenyong, Wang Hanwen, Li Yanping, Xia Tianlong, Yang Jinbo, Ye Yu
State Key Laboratory for Artificial Microstructure & Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing, 100871, China.
MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, 210094, China.
Nat Commun. 2025 May 14;16(1):4465. doi: 10.1038/s41467-025-59690-6.
The recent discovery of anomalous Hall effect (AHE) in non-collinear antiferromagnets offers a promising platform for developing ultra-compact, ultrafast, and low-power antiferromagnetic spintronics, as well as for the in-depth investigation of topological physics. One notable example is the quasi-two-dimensional antiferromagnet CoNbS, which exhibits a large spontaneous Hall effect with compensated magnetization. Here, we report the observation of a large spontaneous Nernst effect in exfoliated CoNbS flakes. By analyzing the temperature- and field-dependent thermoelectric and transport phenomena, we confirm the intrinsic k-space Berry curvature as the origin of the spontaneous Hall effect. Reflective magnetic circular dichroism measurements further reveal the presence of non-collinear antiferromagnetic domains in CoNbS. Combined with electrical transport measurements, we elucidate the distinct magnetic reversal mechanisms between bulk and exfoliated samples. Our study provides a comprehensive phenomenological understanding of the magnetic and transport properties of CoNbS, laying the groundwork for further exploration of the underlying physics and potential applications of two-dimensional non-collinear magnets.
最近在非共线反铁磁体中发现的反常霍尔效应（AHE）为开发超紧凑、超快和低功耗的反铁磁自旋电子学以及深入研究拓扑物理提供了一个很有前景的平台。一个显著的例子是准二维反铁磁体CoNbS，它表现出具有补偿磁化的大自发霍尔效应。在此，我们报告了在剥离的CoNbS薄片中观察到的大自发能斯特效应。通过分析温度和磁场依赖的热电和输运现象，我们确认了本征k空间贝里曲率是自发霍尔效应的起源。反射式磁圆二色性测量进一步揭示了CoNbS中存在非共线反铁磁畴。结合电输运测量，我们阐明了块状和剥离样品之间不同的磁反转机制。我们的研究提供了对CoNbS的磁性和输运性质的全面唯象理解，为进一步探索二维非共线磁体的潜在物理和应用奠定了基础。
