Cai Menghao, Hao Qinghua, Liu Jie, Dai Hongwei, Wang Xia, Chen Xiaodie, Wang Haoyun, Xing Yuntong, Chen Hongjing, Zhang Aoyu, Zhai Tianyou, Han Junbo
Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
ACS Nano. 2024 Jul 26. doi: 10.1021/acsnano.3c11480.
Skyrmions in two-dimensional (2D) magnetic materials are considered as ideal candidates for information carriers in next-generation spintronic devices. However, conventional methods for elucidating the physical properties of skyrmions have limited the development of skyrmions in diverse 2D magnetic material systems due to their requirements for electrical conductivity. To overcome this limitation, we propose to utilize an optical method (magneto-optical Kerr technique) to detect the skyrmions in 2D magnetic materials. Herein, the graphene/FeGeTe/graphene vertical van der Waals (vdW) heterostructure devices are fabricated to generate stabilized skyrmions by applying out-of-plane current. In combination with magnetic circular dichroism measurements, we observe topological-reflective magnetic circular dichroism (T-RMCD) effects in FeGeTe flakes and attribute the peak-shaped component in T-RMCD to the annihilation of skyrmion magnetic domains. Notably, the T-RMCD signal can maintain up to a temperature as high as the Curie temperature of FeGeTe flakes (∼200 K). Our work provides a universal, contactless, and nondestructive approach for studying the physical properties of skyrmions in 2D vdW magnetic materials while adding another degree of freedom to the modulation of skyrmions.
二维（2D）磁性材料中的斯格明子被认为是下一代自旋电子器件中信息载体的理想候选者。然而，由于对电导率的要求，用于阐明斯格明子物理性质的传统方法限制了斯格明子在各种二维磁性材料系统中的发展。为了克服这一限制，我们建议利用光学方法（磁光克尔技术）来检测二维磁性材料中的斯格明子。在此，通过施加面外电流制备了石墨烯/FeGeTe/石墨烯垂直范德华（vdW）异质结构器件，以产生稳定的斯格明子。结合磁圆二色性测量，我们在FeGeTe薄片中观察到拓扑反射磁圆二色性（T-RMCD）效应，并将T-RMCD中的峰形分量归因于斯格明子磁畴的湮灭。值得注意的是，T-RMCD信号可以保持到高达FeGeTe薄片居里温度（约200 K）的温度。我们的工作为研究二维vdW磁性材料中斯格明子的物理性质提供了一种通用、非接触和无损的方法，同时为斯格明子的调制增加了另一个自由度。
