We investigated how different materials affect the orbital-charge conversion in heterostructures with the naturally oxidized cooper capping layer. When we added a thin layer of CuOx(3nm) onto yttrium iron garnet (YIG)/W stacks, we observed a significant reduction in the charge current signal measured by means the spin pumping effect technique. This finding contrasts with the results of a prior study conducted on YIG/Pt/CuOx, which reported the opposite effect. On the other hand, when we added the same CuOx(3nm) layer to YIG/Ti(4nm) structures, there was not much change in the spin pumping signal. This occurred because Ti does not generate much orbital current at the Ti/CuOx interface, unlike Pt, due to its weaker spin-orbit coupling. Interestingly, when we added the CuOx(3nm) layer to SiO2/Py(5nm)/Pt(4nm) structures, the spin pumping signal increased. However, in SiO2/CuOx(3nm)/Pt(4nm)/Py(5nm) structures, the signal decreased. Finally, we delve into a theoretical analysis of the spin (orbital) Hall effect in YIG/Heavy-metal systems. These findings have the potential to advance research in the innovative field of orbitronics and contribute to the development of new technologies based on spin-orbital conversion.
@article{arxiv.2309.08857,
title = {Exploring orbital-charge conversion mediated by interfaces with copper through spin-orbital pumping},
author = {E. Santos and J. E. Abrão and A. S. Vieira and J. B. S. Mendes and R. L. Rodríguez-Suárez and A. Azevedo},
journal= {arXiv preprint arXiv:2309.08857},
year = {2024}
}