非均匀导电磁体中电流的自旋抽运
Spin Pumping of Current in Non-Uniform Conducting Magnets
摘要：
使用不可逆热力学，我们表明，电流引起的自旋转移扭矩内的磁畴意味着自旋泵的电流在该域。这对具有导电引线和电隔离的样品都具有实验意义。这些结果是通过推导两种模型的非均匀导电磁体的动力学方程获得的：（1）一个普通的导电磁体，具有净传导电子密度n和净磁化$\vec{M}$ ;和（2）一个双带磁体，具有向上和向下自旋，每个自旋提供传导和磁性。对于这两种模型，在平衡磁化不均匀的区域，电压梯度可以驱动绝热和非绝热体自旋力矩。昂萨格关系确保了磁矩同样驱动绝热和非绝热电流--我们称之为体自旋泵。对于给定的绝热和非绝热自旋力矩，这两个模型对体自旋抽运产生相似但不同的结果，从而区分这两个模型。正如最近Barnes和Maekawa对自旋Berry相的研究一样，我们发现在畴壁内，有效电动势与磁场的比值近似为$P(2μ_{B}/e)$，其中P是自旋极化。绝热自旋矩和自旋泵项在本质上是耗散的。
英文摘要：
Using irreversible thermodynamics we show that current-induced spin transfer torque within a magnetic domain implies spin pumping of current within that domain. This has experimental implications for samples both with conducting leads and that are electrically isolated. These results are obtained by deriving the dynamical equations for two models of non-uniform conducting magnets: (1) a generic conducting magnet, with net conduction electron density n and net magnetization $\vec{M}$; and (2) a two-band magnet, with up and down spins each providing conduction and magnetism. For both models, in regions where the equilibrium magnetization is non-uniform, voltage gradients can drive adiabatic and non-adiabatic bulk spin torques. Onsager relations then ensure that magnetic torques likewise drive adiabatic and non-adiabatic currents -- what we call bulk spin pumping. For a given amount of adiabatic and non-adiabatic spin torque, the two models yield similar but distinct results for the bulk spin pumping, thus distinguishing the two models. As in the recent spin-Berry phase study by Barnes and Maekawa, we find that within a domain wall the ratio of the effective emf to the magnetic field is approximately given by $P(2μ_{B}/e)$, where P is the spin polarization. The adiabatic spin torque and spin pumping terms are shown to be dissipative in nature.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
