Title: Breakdown of the drift-diffusion model for transverse spin transport in a disordered Pt film Show Chinese title

Title: 横向自旋输运的漂移-扩散模型分解在无序Pt膜中

Abstract: Spin accumulation and spin current profiles are calculated for a disordered Pt film subjected to an in-plane electric current within the nonequilibrium Green function approach. In the bulklike region of the sample, this approach captures the intrinsic spin Hall effect found in other calculations. Near the surfaces, the results reveal qualitative differences with the results of the widely used spin-diffusion model, even when the boundary conditions are modified to try to account for them. One difference is that the effective spin-diffusion length for transverse spin transport is significantly different from its longitudinal counterpart and is instead similar to the mean-free path. This feature may be generic for spin currents generated via the intrinsic spin-Hall mechanism because of the differences in transport mechanisms compared to longitudinal spin transport. Orbital accumulation in the Pt film is only significant in the immediate vicinity of the surfaces and has a small component penetrating into the bulk only in the presence of spin-orbit coupling, as a secondary effect induced by the spin accumulation. Show Chinese abstract

Abstract: 自旋积累和自旋电流分布是在非平衡格林函数方法下计算的，该方法考虑了平面内电流作用下的无序Pt薄膜。 在样品的体区域，这种方法捕捉到了其他计算中发现的本征自旋霍尔效应。 在表面附近，即使修改边界条件以尝试考虑这些因素，结果与广泛使用的自旋扩散模型的结果显示出定性差异。 一个区别是，横向自旋输运的有效自旋扩散长度与其纵向对应值显著不同，而是更类似于平均自由程。 这一特征可能对于通过本征自旋霍尔机制产生的自旋电流是普遍的，这是由于与纵向自旋输运相比，输运机制的不同。 Pt薄膜中的轨道积累仅在表面附近显著，并且只有在存在自旋-轨道耦合的情况下，才会有一个小分量渗透到体内，这是由自旋积累引起的次级效应。