Direct x-ray detection of the spin hall effect in CuBi

Research Projects
Organizational Units
Journal Issue
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 (Cu_(95)Bi_5). 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.
©2022 American Physical Society We thank Roopali Kukreja for answering our questions about Ref. [21] and Sergio O. Valenzuela and Olivier Fruchart for critical reading of the manuscript. We acknowledge M. R. Osorio and D. Granados at IMDEA-nanoscience nanofabri- cation center for their help in the lithography process. This work has been partially funded by MCIN/AEI/10.13039/501100011033 through Projects No. FIS2016-78591-C3-1- R, No. MAT2017-87072-C4-2-P, No. RTI2018-097895-B- C42, No. RTI2018-095303-B-C53, and No. PID2020 - 117024GB-C43 and by the Comunidad de Madrid through Project No. NANOMAGCOST-CM P2018/NMT-4321. IMDEA Nanociencia acknowledges support from the Severo Ochoa Programme for Centres of Excellence in R&D (Grants No. SEV-2016-0686 and No. CEX2020- 001039-S) . The work has been supported by the ALBA in- house research program. We thank the Spanish National Center of Electron Microscopy for Scanning Electron Microscopy measurements. M. W. K. acknowledges funding from Horizon 2020 Marie Sk ? odowska-Curie COFUND DOC-FAM, with Grant agreement No. 754397.