摘要
斯格明子(skyrmion)的概念最早是由英国的粒子物理学家Tony Skyrme提出,它被用来描述粒子的一个状态,是一种拓扑孤立子.磁性斯格明子是一种具有拓扑行为的新型磁结构,其空间尺寸为纳米量级,空间距离从纳米到微米量级可调;其存在温度涵盖从低温、室温到高温的宽温区;其材料体系不仅包括早期发现的低温区B20型中心对称破缺的铁磁体和螺旋磁有序的弱铁磁材料,也包括近期发现的室温及以上的中心对称六角结构磁性MnNiGa金属合金和磁性薄膜/多层膜体系.利用磁性斯格明子的拓扑磁结构可以实现类似于自旋阀或者磁性隧道结中的自旋转移矩效应,即外加电流可以驱动斯格明子,其临界电流密度比传统翻转磁性多层膜体系中磁矩的电流密度(一般为10~7A/cm^2)要低5个数量级,约为10~2A/cm^2,该临界值远低于硅基半导体技术中沟道电流密度的上限,在未来的磁信息技术中具有广泛的应用前景.本综述简单介绍了磁性斯格明子的发展历程,归纳总结了磁性斯格明子的材料体系,介绍了观察磁性斯格明子的实验手段,重点介绍了多场(磁场、电流、温度场)调控作用下中心对称MnNiGa合金和Pt/Co/Ta磁性多层膜体系中磁性斯格明子的产生、消失以及外场调控演变等动态行为.
The concept of skyrmion is proposed by Tony Skyrme, a British particle physicist, to describe a state of particles as a topological soliton. Magnetic skyrmion is a novel spin structure with topological behavior, whose size is on a nanometer scale. The space between skyrmions is tunable from a few nanometers to micrometer. Magnetic skyrmion can be stable in a large temperature range, from lower temperatures, to room temperature, and even to higher temperature.The materials with magnetic skyrmions include not only low temperature B20-type ferromagnets with centrosymmetry breaking and weak ferromagnets with helical magnetic ordering, but also the hexagonal Mn Ni Ga alloy and ferromagnetic multilayers over room temperature. By using topological spin structure of skyrmions, an electrical current can be applied to driving or flipping the skyrmions, similar to the spin transfer torque effect in spin-valves and magnetic tunnel junctions. The critical current density is on the order of 10 2 A/cm2, which is five orders lower than that in magnetic multilayered structures such as 10 7 A/cm2. This critical value is much lower than the channel current density in Si-based semiconductor technology, thus leading to great potential applications in the future magnetic information devices. In this review paper, we first introduce the discovery, a brief development history of magnetic skyrmions. Then, we summarize the materials with skyrmion spin structures, focusing on the key physical properties. Finally, we mention the recent progress of the multi-field（such as magnetic field, electrical current, and temperature） control on magnetic skyrmions in hexagonal Mn Ni Ga alloy and Pt/Co/Ta magnetic multilayers, together with the creation, annihilation, and dynamic behavior of skyrmions.
作者
董博闻
张静言
彭丽聪
何敏
张颖
赵云驰
王超
孙阳
蔡建旺
王文洪
魏红祥
沈保根
姜勇
王守国
Dong Bo-Wen;Zhang Jing-Yan;Peng Li-Cong;He Min;Zhang Ying;Zhao Yun-Chi;Wang Chao;Sun Yang;Cai Jian-Wang;Wang Wen-Hong;Wei Hong-Xiang;Shen Bao-Gen;Jiang Yong;Wang Shou-Guo(Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;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
2018年第13期209-226,共18页
Acta Physica Sinica
基金
国家自然科学基金(批准号:51625101
51431009
51471183
11674373)
国家重点基础研究发展计划(批准号:2015CB921401
2016YFB0700902)
中央高校基本科研业务费(批准号:FRF-TP-16-OO1C2)
中国科学院青年创新促进会(批准号:2015004)资助的课题~~
关键词
斯格明子
拓扑磁性
磁畴结构
磁成像
skyrmions
topological magnetism
magnetic domains
magnetic imaging
