Hou Zhipeng, Wang Yadong, Lan Xiaoming, Li Sai, Wan Xuejin, Meng Fei, Hu Yangfan, Fan Zhen, Feng Chun, Qin Minghui, Zeng Min, Zhang Xichao, Liu Xiaoxi, Fu Xuewen, Yu Guanghua, Zhou Guofu, Zhou Yan, Zhao Weisheng, Gao Xingsen, Liu Jun-Ming
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China.
School of Materials Science and Engineering, Dongguan University of Technology, Dongguan, 523808, P. R. China.
Adv Mater. 2022 Mar;34(11):e2107908. doi: 10.1002/adma.202107908. Epub 2022 Feb 4.
Magnetic skyrmions are topological swirling spin configurations that hold promise for building future magnetic memories and logic circuits. Skyrmionic devices typically rely on the electrical manipulation of a single skyrmion, but controllably manipulating a group of skyrmions can lead to more compact and memory-efficient devices. Here, an electric-field-driven cascading transition of skyrmion clusters in a nanostructured ferromagnetic/ferroelectric multiferroic heterostructure is reported, which allows a continuous multilevel transition of the number of skyrmions in a one-by-one manner. Most notably, the transition is non-volatile and reversible, which is crucial for multi-bit memory applications. Combined experiments and theoretical simulations reveal that the switching of skyrmion clusters is induced by the strain-mediated modification of both the interfacial Dzyaloshinskii-Moriya interaction and effective uniaxial anisotropy. The results not only open up a new direction for constructing low-power-consuming, non-volatile, and multi-bit skyrmionic devices, but also offer valuable insights into the fundamental physics underlying the voltage manipulation of skyrmion clusters.
磁斯格明子是一种拓扑涡旋自旋结构，有望用于构建未来的磁存储器和逻辑电路。斯格明子器件通常依赖于对单个斯格明子的电操控，但可控地操控一组斯格明子可实现更紧凑且存储效率更高的器件。在此，报道了一种电场驱动的纳米结构铁磁/铁电多铁性异质结构中斯格明子簇的级联转变，该转变允许斯格明子数量以逐个方式进行连续多级转变。最值得注意的是，这种转变是非易失性且可逆的，这对于多位存储应用至关重要。结合实验和理论模拟表明，斯格明子簇的开关是由界面Dzyaloshinskii-Moriya相互作用和有效单轴各向异性的应变介导修饰所诱导的。这些结果不仅为构建低功耗、非易失性和多位斯格明子器件开辟了新方向，还为斯格明子簇电压操控背后的基本物理提供了有价值的见解。
