We theoretically study current- and charge-induced spin torques in magnetic Weyl semimetals (WSMs). In magnetic WSMs, a topologically nontrivial band structure mediates the anomalous coupling between magnetization and transport, making WSMs preferable for spintronics systems. In this study, we determine all current-induced spin torques including spin–orbit torque and spin-transfer torque, up to the first order with respect to spatial and temporal derivatives and electrical currents. We also calculate the charge-induced spin torque microscopically. We find that the charge-induced spin torque originates from the chiral anomaly due to the correspondence between spin operators and axial current operators in our model.

中文翻译：

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磁性外尔半金属中电致自旋力矩的微观理论

我们从理论上研究了磁性外尔半金属 (WSM) 中电流和电荷引起的自旋扭矩。在磁性 WSM 中，拓扑上非平凡的带结构介导了磁化和输运之间的异常耦合，使 WSM 更适合自旋电子学系统。在这项研究中，我们确定了所有电流引起的自旋扭矩，包括自旋轨道扭矩和自旋转移扭矩，直到关于空间和时间导数和电流的一阶。我们还通过显微镜计算了电荷诱导的自旋扭矩。我们发现，由于我们模型中自旋算子和轴向电流算子之间的对应关系，电荷引起的自旋扭矩源自手性异常。