Chiral spin-wave velocities induced by all-garnet interfacial Dzyaloshinskii-Moriya interaction in ultrathin yttrium iron garnet films
Chiral spin-wave velocities induced by all-garnet interfacial Dzyaloshinskii-Moriya interaction in ultrathin yttrium iron garnet films
复制标题
超薄钇铁石榴石薄膜中全石榴石界面 Dzyaloshinskii-Moriya 相互作用诱导的手性自旋波速度
DOI：
10.1103/physrevlett.124.027203
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发表时间：
2020
影响因子：
8.6
通讯作者：
Haiming Yu
中科院分区：
文献类型：
--
作者：
Hanchen Wang;Jilei Chen;Tao Liu;Jianyu Zhang;Korbinian Baumgaertl;Chenyang Guo;Yuehui Li;Chuanpu Liu;Ping Che;Sa Tu;Song Liu;Peng Gao;Xiufeng Han;Dapeng Yu;Mingzhong Wu;Dirk Grundler;Haiming Yu
自旋波可以探测Dzyaloshinskiii-Moriya相互作用（Dzyaloshinskiii-Moriya interaction），这会产生拓扑自旋纹理，例如skyrmions。然而，在钇铁石榴石（YIG）中还没有报道过这种自旋波阻尼最低的材料。在这项工作中，我们通过测量非互易自旋波传播的频率，振幅，最重要的是群速度，使用全电自旋波光谱实验证明在7 nm厚的YIG膜的界面的介电常数。传播自旋波的速度在三个矢量之间表现出手征性，即，薄膜法线方向、外加场和自旋波波矢量。通过测量非对称群速度，我们提取了一个常数，我们独立确认布里渊光散射。厚度相关的测量结果表明，YIG和石榴石衬底之间的氧化物界面起源的。在YIG薄膜中发现的界面微扰对于功能性手征磁振子具有重要意义，因为它可以实现超低的自旋波阻尼。
Spin waves can probe the Dzyaloshinskii-Moriya interaction (DMI), which gives rise to topological spin textures, such as skyrmions. However, the DMI has not yet been reported in yttrium iron garnet (YIG) with arguably the lowest damping for spin waves. In this work, we experimentally evidence the interfacial DMI in a 7-nm-thick YIG film by measuring the nonreciprocal spin-wave propagation in terms of frequency, amplitude, and most importantly group velocities using all electrical spin-wave spectroscopy. The velocities of propagating spin waves show chirality among three vectors, i.e., the film normal direction, applied field, and spin-wave wave vector. By measuring the asymmetric group velocities, we extract a DMI constant of, which we independently confirm by Brillouin light scattering. Thickness-dependent measurements reveal that the DMI originates from the oxide interface between the YIG and garnet substrate. The interfacial DMI discovered in the ultrathin YIG films is of key importance for functional chiral magnonics as ultralow spin-wave damping can be achieved.