Angular dependence of spin-orbit torque in monolayer Fe3GeTe2
Angular dependence of spin-orbit torque in monolayer Fe3GeTe2
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DOI：
10.1103/physrevb.108.144422
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发表时间：
2023-07
影响因子：
3.7
通讯作者：
F. Xue;M. Stiles;P. Haney
中科院分区：
文献类型：
--
作者：
F. Xue;M. Stiles;P. Haney
在缺乏反转对称性的铁磁系统中，外加电场可以通过自旋-轨道矩控制铁磁序参量。典型的例子是由铁磁体和重金属组成的双层异质结构，其充当自旋电流源。除了这样的双层，自旋-轨道耦合可以介导缺乏体反转对称性的铁磁体中的自旋-轨道扭矩。最近发现的一个例子是二维单层铁磁体$Fe_3GeTe_2$。在这项工作中，我们使用第一性原理计算来研究这种材料中的自旋轨道扭矩和随之而来的磁动力学。通过扩展的扭矩与磁化方向作为一系列的矢量球谐函数，我们发现，高阶项（高达$\ell=4$）是显着的，并发挥重要作用的磁动力学。它们产生确定性的、无磁场的垂直磁化的电开关。
In ferromagnetic systems lacking inversion symmetry, an applied electric field can control the ferromagnetic order parameters through the spin-orbit torque. The prototypical example is a bilayer heterostructure composed of a ferromagnet and a heavy metal that acts as a spin current source. In addition to such bilayers, spin-orbit coupling can mediate spin-orbit torques in ferromagnets that lack bulk inversion symmetry. A recently discovered example is the two-dimensional monolayer ferromagnet $Fe_3GeTe_2$. In this work, we use first-principles calculations to study the spin-orbit torque and ensuing magnetic dynamics in this material. By expanding the torque versus magnetization direction as a series of vector spherical harmonics, we find that higher order terms (up to $\ell=4$) are significant and play important roles in the magnetic dynamics. They give rise to deterministic, magnetic field-free electrical switching of perpendicular magnetization.