L.B acknowledges the European Union's Horizon 2020 research and innovation program
under the Marie Skłodowska-Curie grant agreements ARTES number 793159. L.B., A.R.,
S.D., M.F. and M.K. acknowledge support from the Graduate School of Excellence Materials
Science in Mainz (MAINZ) DFG 266, the DAAD (Spintronics network, Project No.
57334897) and all groups from Mainz acknowledge that this work was funded by the
Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - TRR 173 –
268565370 (projects A01 and B02) and KAUST (OSR-2019-CRG8-4048). M.K.
acknowledges financial support from the Horizon 2020 Framework Programme of the
European Commission under FET-Open grant agreement no. 863155 (sNebula). We
acknowledge Diamond Light Source for time on beamline I06 under proposals MM22448 and
MM23819-1. This work was also supported by ERATO "Spin Quantum Rectification
Project" (Grant No. JPMJER1402) and the Grant-in-Aid for Scientific Research on Innovative
Area, "Nano Spin Conversion Science" (Grant No. JP26103005), Grant-in-Aid for Scientific
Research (S) (Grant No. JP19H05600) from JSPS KAKENHI, R.R. also acknowledges
support by Grant-in-Aid for Scientific Research (C) (Grant No. JP20K05297) from JSPS
KAKENHI, Japan. This work was supported by the Max Planck Graduate Centre with the
Johannes Gutenberg Universität Mainz (MPGC).