Thermoelectric microscopy of magnetic skyrmions
Thermoelectric microscopy of magnetic skyrmions
复制标题
DOI：
10.1038/s41598-019-54833-4
复制
发表时间：
2019-12-05
影响因子：
4.6
通讯作者：
Uchida，Ken-ichi
中科院分区：
文献类型：
--
作者：
Iguchi，Ryo;Kasai，Shinya;Uchida，Ken-ichi
磁skyrmion是一种纳米级的拓扑对象，其特征是磁矩的缠绕，出现在具有破缺反转对称性的磁性材料中。由于其驱动Skyrmion运动的低电流阈值，它们已经通过使用电子束，X射线和可见光显微镜对新的存储应用进行了深入的研究。在这里，我们利用自旋热子现象，即自旋塞贝克效应和异常能斯特效应，作为磁纹理的探针，展示了另一种Skyrmion成像方法。我们在一个霍尔十字形的MgO/CoFeB/Ta/W多层膜上扫描了一个聚焦的加热点，并绘制了由于自旋热电子现象而产生的热电流的大小和方向。我们的实验和计算表明，热电信号分布的特征图案反映了Skyrmion的磁织构。由于自旋-热电子现象的独特对称性，热电显微镜将成为一种互补的和有用的成像技术，用于Skyrmion器件的发展。
The magnetic skyrmion is a nanoscale topological object characterized by the winding of magnetic moments, appearing in magnetic materials with broken inversion symmetry. Because of its low current threshold for driving the skyrmion motion, they have been intensely studied toward novel storage applications by using electron-beam, X-ray, and visible light microscopies. Here, we demonstrate another imaging method for skyrmions by using spin-caloritronic phenomena, that is, the spin Seebeck and anomalous Nernst effects, as a probe of magnetic texture. We scanned a focused heating spot on a Hall-cross shaped MgO/CoFeB/Ta/W multilayer film and mapped the magnitude as well as the direction of the resultant thermoelectric current due to the spin-caloritronic phenomena. Our experimental and calculation reveal that the characteristic patterns in the thermoelectric signal distribution reflect the skyrmions’ magnetic texture. The thermoelectric microscopy will be a complementary and useful imaging technique for the development of skyrmion devices owing to the unique symmetry of the spin-caloritronic phenomena.