摘要
拓扑磁性斯格明子作为信息载体单元具备高可靠性、高集成度、低能耗等优势,有望提高数据读写精度、降低功耗,从而研发新型拓扑自旋电子学材料与原理型器件,为信息技术、5G通信和大数据等的高速发展提供材料与技术支持.但磁性斯格明子同时存在需要磁场稳定以及电流驱动下斯格明子霍尔效应引起偏转等缺点,严重阻碍了其在实际器件中的应用,因此探索新型拓扑磁畴结构和适宜应用的材料体系成为研究的关键.本文将重点介绍自2013年理论预言磁畴壁斯格明子以来,利用高分辨率洛伦兹透射电子显微镜原位实空间发现并研究磁畴壁拓扑麦纫和磁畴壁斯格明子的实验工作.首次在范德瓦耳斯Fe_(5–x)GeTe_(2)二维磁性材料中发现温度诱发的180°磁畴壁转变为拓扑麦韧链,研究了磁畴壁麦纫态在外界电场、磁场作用下的集体运动行为,揭示了基于自旋重取向、磁畴壁限域效应以及弱相互作用下生成磁畴壁拓扑态的机制.在该机制指导下,设计制备了具有自旋重取向的GdFeCo非晶亚铁磁薄膜,不仅获得了磁畴壁麦纫,验证了生成机制的普适性,还成功实现了畴壁麦韧对到畴壁斯格明子的可逆拓扑转变,开辟了基于磁畴壁等内禀限域效应开展拓扑磁性物态探索和研究的新方向.
Topological magnetic skyrmions,as information units,possess distinct advantages such as high reliability,enhanced integration,and low energy consumption.These novel topological characteristics offer critical material and technological support for the rapid development of information technology,5G communication,and big data.However,the application of magnetic skyrmions in practical devices is severely impeded by certain limitations,including their stability dependence on magnetic field and the deflection caused by the skyrmion Hall effect under electric current.Consequently,exploring new topological magnetic domain structures and material systems suitable for application becomes a pivotal area of research.This paper primarily focuses on experimental studies utilizing high-resolution Lorentz transmission electron microscopy for in situ real-space observation and manipulation of topological merons and skyrmions inside the magnetic domain wall,confirming the theoretical prediction of magnetic domain wall skyrmions in 2013.We has firstly achieved topological meron chains inside the domain walls by using the spin reorientation transition in two-dimensional van der Waals Fe_(5–x)GeTe_(2) magnets,and systematically studied the dynamic behavior of domain wall topological magnetic domain structures under external electric and magnetic fields,filling the blanks in this research area.The important and special roles of magnetic domain walls are revealed at the same time.Then the GdFeCo amorphous ferrimagnetic thin film was designed and prepared based on the summarized mechanism with the domain wall meron pairs successfully reproduced.Moreover,the reversible topological transformation from domain wall meron pair to domain wall skyrmions has also been realized without external magnetic field during spin reorientation transformation as temperature changing.The results of micromagnetic simulation and electric experiments on the topological domains in domain walls would provided a strong basis and support for the future research.
作者
张颖
李卓霖
沈保根
Zhang Ying;Li Zhuo-Lin;Shen Bao-Gen(State Key Laboratory of Magnetism,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第1期57-68,共12页
Acta Physica Sinica
基金
中国科学院先导计划(批准号:XDB33030100)
中国科学院稳定支持基础研究领域青年团队计划(批准号:YSBR-084)资助的课题
国家自然科学基金科学中心(批准号:52088101)
国家自然科学基金(批准号:52271195,52130103)。
关键词
磁畴壁麦纫
磁畴壁斯格明子
自旋重取向
洛伦兹透射电子显微镜
二维磁性材料
magnetic domain wall meron
magnetic domain wall skyrmion
spin reorientation transition
Lorentz transmission electron microscopy
two-dimensional magnet
