Direct X-ray detection of the spin Hall effect in CuBi

TL;DR

This study demonstrates direct, interface-free x-ray spectroscopy detection of the spin Hall effect in CuBi, revealing induced magnetic moments and emphasizing the importance of interface-free methods for accurate material characterization in spintronics.

Contribution

First direct x-ray detection of the spin Hall effect in CuBi without interface artifacts, advancing understanding of spin-charge conversion mechanisms.

Findings

Detected magnetic moments consistent with spin Hall effect in CuBi

Interface-free measurements reduce scattering and improve accuracy

CuBi shows potential for spin-charge conversion applications

Abstract

The spin Hall effect and its inverse 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 non-magnetic 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 (Cu_{95}Bi_{5}). The detected X-ray magnetic circular dichroism (XMCD) signal corresponds to an induced magnetic moment of (2.7 +/- 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 as 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.