Exploring orbital-charge conversion mediated by interfaces with copper through spin-orbital pumping

E. Santos; J. E. Abrão; A. S. Vieira; J. B. S. Mendes; R. L. Rodríguez-Suárez; A. Azevedo

doi:10.1103/PhysRevB.109.014420

paper

Exploring orbital-charge conversion mediated by interfaces with copper through spin-orbital pumping

arXiv:2309.08857 · doi:10.1103/PhysRevB.109.014420

Abstract

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 $C u O x (3 nm)$ onto yttrium iron garnet $(Y I G) / W$ 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 $C u O x (3 nm)$ layer to $Y I G / T i (4 nm)$ structures, there was not much change in the spin pumping signal. This occurred because Ti does not generate much orbital current at the $T i / C u O x$ interface, unlike Pt, due to its weaker spin-orbit coupling. Interestingly, when we added the $C u O x (3 nm)$ layer to $S i O_{2} / P y (5 nm) / P t (4 nm)$ structures, the spin pumping signal increased. However, in $S i O_{2} / C u O x (3 nm) / P t (4 nm) / P y (5 nm)$ 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.

21 pages, 6 figures,