Direct observation of anisotropic magnetic field response of the spin helix in FeGe thin films
Direct observation of anisotropic magnetic field response of the spin helix in FeGe thin films
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DOI：
10.1103/physrevb.94.184432
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发表时间：
2016-11
影响因子：
3.7
通讯作者：
N. Kanazawa;J. White;H. Rønnow;C. Dewhurst;Y. Fujishiro;A. Tsukazaki;Y. Kozuka;M. Kawasaki;M. Ichikawa;F. Kagawa;Y. Tokura
中科院分区：
文献类型：
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作者：
N. Kanazawa;J. White;H. Rønnow;C. Dewhurst;Y. Fujishiro;A. Tsukazaki;Y. Kozuka;M. Kawasaki;M. Ichikawa;F. Kagawa;Y. Tokura
螺旋自旋序通过与电子结构的相互作用经常产生各种有趣的现象。实例包括但不限于多铁性和skyrmion形成。其中，变形螺旋结构可以看作是一系列的自旋-旋转扭结，由于其相位相干性，可以实现信息传输功能.这就是手征磁孤立子晶格（CSL）。在这里，作者成功地在手性磁体FeGe的薄膜中构建了自旋螺旋，并揭示了其特征磁响应。外延薄膜固有的磁各向异性和边界条件确保了螺旋缠绕方向沿着膜法线的对准，即使在外部磁场下也是如此。这种约束导致自旋螺旋相对于磁场方向的各向异性变形。特别地，在面内磁场下实现的CSL在具有不同数目扭结的状态之间随场变换。作者清楚地证明了变形的螺旋传播矢量的直接观察使用小角中子散射技术。
Spiral spin orders often produce various fascinating phenomena via interaction with electronic structures. Examples include, but are not limited to, multiferroicity and skyrmion formation. Among them, a deformed spiral spin structure, which can be viewed as a periodic sequence of 2$\ensuremath{\pi}$ spin-rotation kinks, can exhibit the functionality of information transmission owing to its phase coherence. This is the chiral magnetic soliton lattice (CSL). Here, the authors have succeeded in building a spin spiral in a thin film of the chiral magnet FeGe, and revealed its characteristic magnetic responses. Magnetic anisotropy and boundary conditions inherent to the epitaxial thin film secure the alignment of the spiral winding direction along the film normal, even under external magnetic fields. This constraint leads to the anisotropic deformation of the spin spiral with respect to the magnetic field direction. Especially, the CSL, which is realized under an in-plane magnetic field, transforms with field between states with different numbers of kinks. The authors clearly demonstrate the deformation by direct observation of the spiral propagation vector by use of the small-angle neutron scattering technique.