Zhang Senfu, Zhang Xichao, Zhang Junwei, Ganguly Arnab, Xia Jing, Wen Yan, Zhang Qiang, Yu Guoqiang, Hou Zhipeng, Wang Wenhong, Peng Yong, Xiao Gang, Manchon Aurelien, Kosel Jürgen, Zhou Yan, Zhang Xi-Xiang
Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China.
Sci Adv. 2020 Feb 7;6(6):eaay1876. doi: 10.1126/sciadv.aay1876. eCollection 2020 Feb.
The direct imaging of current density vector distributions in thin films has remained a daring challenge. Here, we report that an inhomogeneous current distribution can be mapped directly by the trajectories of magnetic half-skyrmions driven by an electrical current in Pt/Co/Ta trilayer, using polar magneto-optical Kerr microscopy. The half-skyrmion carries a topological charge of 0.5 due to the presence of Dzyaloshinskii-Moriya interaction, which leads to the half-skyrmion Hall effect. The Hall angle of half-skyrmions is independent of current density and can be reduced to as small as 4° by tuning the thickness of the Co layer. The Hall angle is so small that the elongation path of half-skyrmion approximately delineates the invisible current flow as demonstrated in both a continuous film and a curved track. Our work provides a practical technique to directly map inhomogeneous current distribution even in complex geometries for both fundamental research and industrial applications.
对薄膜中电流密度矢量分布进行直接成像一直是一项极具挑战性的任务。在此，我们报告利用极磁光克尔显微镜，通过铂/钴/钽三层膜中电流驱动的磁半斯格明子轨迹，可以直接绘制非均匀电流分布。由于存在Dzyaloshinskii-Moriya相互作用，半斯格明子携带拓扑电荷0.5，这导致了半斯格明子霍尔效应。半斯格明子的霍尔角与电流密度无关，通过调整钴层厚度可将其减小至4°。霍尔角如此之小，以至于半斯格明子的伸长路径大致描绘出了不可见的电流流动，这在连续薄膜和弯曲轨道中都得到了证明。我们的工作提供了一种实用技术，即使在复杂几何结构中，也能直接绘制非均匀电流分布，适用于基础研究和工业应用。
