Theory of spin-polarized thermal transport in ferromagnetic metallic heterostructures

铁磁金属自旋极化热输运的实验研究取得了重要进展。在这份提案中，我们要求提供资金，对铁磁金属异质结构中的自旋极化热输运进行系统和全面的计算。在唯象水平上，我们将标准的自旋注入模型推广到实际器件中的热流，研究边界条件对自旋积累和自旋霍尔电压的影响.此外，我们计划研究交流和瞬态现象，这将提供有关自旋弛豫过程和热诱导自旋积累的重要信息。在特定的目标是找到现实的自旋Seebeck系数在F/N/F结，在各种制度的接触和隧穿电阻，给基准，以挑选出电子和磁振子的贡献检测到的自旋电压信号。我们还将研究具有空间电荷的系统，如肖特基势垒和铁磁结二极管和晶体管;在这些系统中，自旋极化热输运的标准理论必须推广到包括（自洽）内置电场。在微观层次上，我们将研究磁振子阻力和自旋-声子阻力，以及它们与铁磁金属异质结构中的热输运和自旋输运的相互作用。这些机制的热电和控制系统参数的相关性将建立通过开发微观模型计算。将特别注意这些机制在F/N界面的作用。结结构反转不对称的无序和自旋轨道相互作用的影响也将纳入。特别是，我们将探讨新的现象出现的SOI和阻力机制的联合行动的可能性。这些计算将通过使用玻尔兹曼和久保线性响应形式化来进行。所得结果将用于补充热自旋注入的唯象理论。

There has been significant experimental progress on investigating spin-polarized thermal transport in ferromagnetic metals. In this proposal we request funding to perform system-atic and comprehensive calculations of the spin-polarized thermal transport in ferromag-netic metal heterostructures. On a phenomenological level, we will generalize the stan-dard spin injection model to include thermal currents in realistic device settings, investi-gate the effects of the boundary conditions on the spin accumulation and the spin Hall voltages in these systems. In addition, we plan to study ac and transient phenomena which will provide important information about the spin relaxation processes and thermally induce spin accumulation. Among particular goals are finding realistic spin Seebeck coef-ficients in the F/N/F junctions, in various regimes of contact and tunneling resistances, to give the benchmark to sort out electronic and magnonic contributions to the detected spin voltage signals. We will also investigate systems with space charges, such as Schottky barriers and ferromagnetic junction diodes and transistors; in these systems the standard theory of the spin-polarized thermal transport has to be generalized to include (self-consistently) the built in electric fields. On a microscopic level, we will investigate the magnon drag and the spin-phonon drag and their interplay with thermal and spin transport in ferromagnetic metallic heterostructures. The relevance of these mechanisms for the thermopower and the control system parameters will be established by developing micro-scopic model calculations. Special attention will be devoted to the role of these mecha-nisms at the F/N interfaces. The effects of disorder and spin-orbit interaction in junctions with structure inversion asymmetry will also be incorporated. In particular, we will explore the possibility of new phenomena emerging from the combined action of the SOI and the drag mechanisms. These calculations will be performed by using both the Boltzmann and Kubo linear-response formalisms. The obtained results will be used to complement the phenomenological theory of thermal spin injection.