Long-range chiral exchange interaction in synthetic antiferromagnets
Long-range chiral exchange interaction in synthetic antiferromagnets
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DOI：
10.1038/s41563-019-0370-z
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发表时间：
2019-07-01
期刊：
影响因子：
41.2
通讯作者：
Klaeui, Mathias
中科院分区：
文献类型：
--
作者：
Han, Dong-Soo;Lee, Kyujoon;Klaeui, Mathias
交换作用支配着静态和动态的磁性。这种基本的相互作用有两种形式--对称和反对称。对称相互作用导致铁磁性和反铁磁性，而反对称相互作用由于其在促进拓扑非平凡自旋织构方面的主要作用而引起人们的极大兴趣，这些自旋织构有望实现快速、节能的器件。到目前为止，已经发现反对称交换相互作用是相当短的范围并且局限于单个磁层。本文报道了具有平行和反平行磁化排列的垂直磁化合成反铁磁体中的长程反对称层间交换相互作用。面内磁场下的非对称磁滞回线揭示了这种相互作用的单向性和手性，从而导致了倾斜的磁性结构。我们通过考虑多层膜中的自旋-轨道耦合和约化对称性来解释我们的结果。我们的长程手性相互作用的发现为设计磁性结构提供了额外的手段，并可能使三维拓扑结构成为可能。
The exchange interaction governs static and dynamic magnetism. This fundamental interaction comes in two flavours-symmetric and antisymmetric. The symmetric interaction leads to ferro- and antiferromagnetism, and the antisymmetric interaction has attracted significant interest owing to its major role in promoting topologically non-trivial spin textures that promise fast, energy-efficient devices. So far, the antisymmetric exchange interaction has been found to be rather short ranged and limited to a single magnetic layer. Here we report a long-range antisymmetric interlayer exchange interaction in perpendicularly magnetized synthetic antiferromagnets with parallel and antiparallel magnetization alignments. Asymmetric hysteresis loops under an in-plane field reveal a unidirectional and chiral nature of this interaction, which results in canted magnetic structures. We explain our results by considering spin-orbit coupling combined with reduced symmetry in multilayers. Our discovery of a long-range chiral interaction provides an additional handle to engineer magnetic structures and could enable three-dimensional topological structures.