标题： 铁磁金属中磁子拖曳电子流的微观理论 显示英文标题

标题： Microscopic theory of magnon-drag electron flow in ferromagnetic metals

摘要： 一个温度梯度施加在铁磁金属上，不仅会引起电子和磁振子的独立流动，还会由于它们的相互作用而产生拖曳电流。 在本文中，我们对由磁振子引起的拖曳所诱导的电子流动进行了微观研究。 分析基于 $s$-$d$ 模型，该模型描述了通过 $s$-$d$ 交换相互作用耦合的传导电子和磁振子。 磁杂质被引入电子子系统作为自旋弛豫的来源。 获得的磁子拖拽电子电流与磁子的熵以及$\alpha - \beta$（更准确地说，是$1 - \beta/\alpha$）成正比，其中$\alpha$是 Gilbert 阻尼常数，$\beta$是耗散性自旋转移扭矩参数。 这一结果几乎与基于磁子电动势的先前经验结果一致，并包括自旋转移和动量转移贡献，但在前者存在轻微不一致。 该结果被解释为非平衡磁子产生的非平衡自旋化学势。 显示英文摘要

摘要： A temperature gradient applied to a ferromagnetic metal induces not only independent flows of electrons and magnons but also drag currents because of their mutual interaction. In this paper, we present a microscopic study of the electron flow induced by the drag due to magnons. The analysis is based on the $s$-$d$ model, which describes conduction electrons and magnons coupled via the $s$-$d$ exchange interaction. Magnetic impurities are introduced in the electron subsystem as a source of spin relaxation. The obtained magnon-drag electron current is proportional to the entropy of magnons and to $\alpha - \beta$ (more precisely, to $1 - \beta/\alpha$), where $\alpha$ is the Gilbert damping constant and $\beta$ is the dissipative spin-transfer torque parameter. This result almost coincides with the previous phenomenological result based on the magnonic spin-motive forces, and consists of spin-transfer and momentum-transfer contributions, but with a slight disagreement in the former. The result is interpreted in terms of the nonequilibrium spin chemical potential generated by nonequilibrium magnons.