Direct X-Ray Detection of the Spin Hall Effect in CuBi

The spin Hall effect and the inverse spin Hall effect are important spin-charge conversion mechanisms. The direct spin Hall effect induces a surface spin accumulation from a transverse charge current due to spin-orbit coupling even in nonmagnetic conductors. However, most detection schemes involve additional interfaces, leading to large scattering in reported data. Here we perform interface-free x-ray spectroscopy measurements at the Cu L-3;2 absorption edges of highly Bi-doped Cu (Cu95Bi5). The detected x-ray magnetic circular dichroism signal corresponds to an induced magnetic moment of (2.2 + 0.5) x 10(-12) mu(B) A(-1) cm(2) per Cu atom averaged over the probing depth, which is of the same order of magnitude as found for Pt measured by magneto-optics. The results highlight the importance of interface-free measurements to assess material parameters and the potential of CuBi for spin-charge conversion applications.

Automated summary

The spin Hall effect and the inverse spin Hall effect are important spin-charge conversion mechanisms. The direct spin Hall effect can induce surface spin accumulation in nonmagnetic conductors. However, most detection schemes involve interfaces, resulting in considerable scattering in the reported data. Interface-free measurements on highly Bi-doped Cu (Cu95Bi5) using x-ray spectroscopy reveal a similar induced magnetic moment as that of Pt measured by magneto-optics, highlighting the potential of CuBi for spin-charge conversion applications.