We present an effect of the spin-orbit interaction (SOI) at surrounding atoms on K-edge magnetic extended x-ray absorption fine structure (MEXAFS). A contribution of the SOI to a K-edge MEXAFS spectrum is described by a perturbative way within a multiple scattering (MS) theory. A numerical calculation shows that a photoelectron single scattering by the SOI at surrounding atomic sites has a negligibly small contribution to MEXAFS. Although a negligible contribution of the SOI at surrounding atoms has been attributed to a cancellation of various MS contributions, this small contribution can be understood by the small number of its effective partial wave components, at least within the single scattering approximation. For further detailed analyses of MS with a path expansion method, only the small number of the partial wave components for the SOI is necessary. This leads to faster computations for MEXAFS including the photoelectron scattering by the SOI.

中文翻译：

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自旋轨道相互作用对磁 EXAFS 光电子散射过程的影响

我们展示了周围原子的自旋轨道相互作用 (SOI) 对 K 边磁性扩展 X 射线吸收精细结构 (MEXAFS) 的影响。SOI 对 K 边缘 MEXAFS 光谱的贡献通过多重散射 (MS) 理论中的微扰方式进行描述。数值计算表明，SOI 在周围原子位点的光电子单次散射对 MEXAFS 的贡献微乎其微。尽管 SOI 对周围原子的贡献可以忽略不计，这归因于各种 MS 贡献的抵消，但可以通过其有效分波分量的数量少来理解这种小贡献，至少在单散射近似内是这样。对于使用路径扩展方法对 MS 进行更详细的分析，只需要少量的 SOI 部分波分量。这导致 MEXAFS 的计算速度更快，包括 SOI 的光电子散射。