Magnetic skyrmions without the skyrmion Hall effect in a magnetic nanotrack with perpendicular anisotropy
Magnetic skyrmions without the skyrmion Hall effect in a magnetic nanotrack with perpendicular anisotropy
复制标题
具有垂直各向异性的磁性纳米轨道中没有斯格明子霍尔效应的磁性斯格明子
作者：
Zhang Yue;Luo Shijiang;Yan Baiqian;Ou-Yang Jun;Yang Xiaofei;Chen Shi;Zhu Benpeng;You Long
磁性Skyrmions在新型信息器件中具有潜在的应用价值。然而，Skyrmion霍尔效应（SkHE）可能导致在纳米轨道中移动的Skyrmion在轨道边缘被湮灭。在这项工作中，我们发现SkHE是通过修改轨道边缘的磁结构来压低的，因此Skyrmion可以以几乎直线的速度运动。与具有垂直磁各向异性的轨道的内部不同，边缘层具有面内磁各向异性，并且边缘力矩的取向与附近skyrmions的周边相反。因此，一个增强的排斥力作用在Skyrmion上，以对抗导致SkHE的马格努斯力。此外，边缘层的Dzyaloshinskiii-Moriya相互作用常数也很重要。当边缘层不存在边界层时，当边缘层的宽度足够大时，可以有效地抑制skyrmion的横向位移。而当内层和边缘具有相同的阻尼常数时，由于边缘层的Néel壁结构，产生了非单调变化的横向位移。
Magnetic skyrmions have potential applications in novel information devices with excellent energy efficiency. However, the skyrmion Hall effect (SkHE) could cause skyrmions moving in a nanotrack to get annihilated at the track edge. In this work, we discovered that the SkHE is depressed by modifying the magnetic structure at the edge of a track, and thus the skyrmion can move in almost a straight line at a high speed. Unlike the inner part of a track with perpendicular magnetic anisotropy, the edge layer exhibits in-plane magnetic anisotropy, and the orientation of edge moments is opposite that at the perimeter of skyrmions nearby. As a result, an enhanced repulsive force acts on the skyrmion to oppose the Magnus force that causes the SkHE. Additionally, the Dzyaloshinskii–Moriya interaction (DMI) constant of the edge layer also matters. When there is no DMI at the edge layer, the transverse displacement of the skyrmion can be depressed effectively when the width of the edge layer is sufficiently large. However, when the inner part and the edge share the same DMI constant, non-monotonically varied transverse displacement occurs because of the Néel-wall-like structure at the edge layer.