First-principles calculations of spin-orbit torques in Mn2Au /heavy-metal bilayers
First-principles calculations of spin-orbit torques in Mn2Au /heavy-metal bilayers
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DOI：
10.1103/physrevb.105.064412
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发表时间：
2021-11
影响因子：
3.7
通讯作者：
W. Fang;K. Belashchenko
中科院分区：
文献类型：
--
作者：
W. Fang;K. Belashchenko
使用非平衡格林函数技术，我们计算了 Mn 2 Au/重金属双层中的自旋轨道扭矩，其中重金属 (HM) 是 W 或 Pt。 Mn 2 Au 块体中的自旋轨道耦合 (SOC) 会产生强场状扭矩，该扭矩在两个子晶格上平行，并与电导率成线性比例，以及较弱的类阻尼扭矩，在两个子晶格上反平行。与 W 或 Pt 的界面产生符号相反的平行阻尼扭矩，其大小与铁磁双层中的扭矩相似，并且对无序同样不敏感。类阻尼扭矩效率很大程度上取决于界面的终止和 Mn 2 Au 中自旋轨道耦合的存在，这表明类阻尼扭矩不仅仅归因于 HM 层中的自旋霍尔效应。界面还会引起反平行场和阻尼类扭矩，这些扭矩可以深入渗透到 Mn 2 Au 中。
Using the non-equilibrium Green’s function technique, we calculate spin-orbit torques in a Mn 2 Au/heavy-metal bilayer, where the heavy metal (HM) is W or Pt. Spin-orbit coupling (SOC) in the bulk of Mn 2 Au generates a strong fieldlike torquance, which is parallel on the two sublattices and scales linearly with the conductivity, and a weaker dampinglike torquance that is antiparallel on the two sublattices. Interfaces with W or Pt generate parallel dampinglike torques of opposite signs that are similar in magnitude to those in ferromagnetic bilayers and similarly insensitive to disorder. The dampinglike torque efficiency depends strongly on the termination of the interface and on the presence of spin-orbit coupling in Mn 2 Au, suggesting that the dampinglike torque is not due solely to the spin-Hall effect in the HM layer. Interfaces also induce antiparallel fieldlike and dampinglike torques that can penetrate deep into Mn 2 Au.