标题： 绝热自旋和轨道泵浦在金属异质结构中 显示英文标题

标题： Adiabatic Spin and Orbital Pumping in Metallic Heterostructures

摘要： 在本研究中，我们研究了平面双层异质结构中磁化动力学引起的自旋和轨道密度。 为此，我们采用了一种使用Keldysh形式和Wigner展开的绝热泵理论。 我们首先对模型系统进行模拟，以确定控制自旋和轨道泵入相邻非磁性金属的参数。 我们得出结论，在原则上，当铁磁体中存在自旋-轨道耦合时，轨道泵可以与自旋泵同样显著。 我们通过第一性原理计算将研究扩展到涉及重金属（W、Pt、Au）和轻金属（Ti、Cu）的实际异质结构。 我们证明，在费米能级附近具有$d$状态的金属中，如Ti、Pt和W，轨道泵被促进，但在缺乏此类状态的材料中，如Cu和Au，轨道泵被抑制。 在具有强自旋-轨道耦合的材料中，轨道注入也被促进，导致Ni/(Pt、W)双层中的大轨道泵。 显示英文摘要

摘要： In this study, we investigate the spin and orbital densities induced by magnetization dynamics in a planar bilayer heterostructure. To do this, we employed a theory of adiabatic pumping using the Keldysh formalism and Wigner expansion. We first conduct simulations on a model system to determine the parameters that control the spin and orbital pumping into an adjacent non-magnetic metal. We conclude that, in principle, the orbital pumping can be as significant as spin pumping when the spin-orbit coupling is present in the ferromagnet. We extend the study to realistic heterostructures involving heavy metals (W, Pt, Au) and light metals (Ti, Cu) by using first-principles calculations. We demonstrate that orbital pumping is favored in metals with $d$ states close to the Fermi level, such as Ti, Pt, and W, but is quenched in materials lacking such states, such as Cu and Au. Orbital injection is also favored in materials with strong spin-orbit coupling, leading to large orbital pumping in Ni/(Pt, W) bilayers.