arXiv subjects

R. L. Rodríguez-Suárez

Publications and source records attributed to R. L. Rodríguez-Suárez.

4 recordsLinked to original sources

arXiv2026

Orbital to charge current conversion in copper oxide heterostructures

We investigate the orbital-to-charge current conversion in CoFeB|CuO bilayers as a function of CuO thickness, employing orbital pumping via ferromagnetic resonance. The dynamic injection of orbital angular momentum into the CuO layer generates a transverse voltage through the Inverse Orbital Hall Effect (IOHE). By systematically varying the CuO thickness from 2 nm to 30 nm, we observe a pronounced dependence of the IOHE-induced voltage on the CuO layer thickness, indicating efficient orbital-to-charge conversion. These results highlight the key role of the orbital degree of freedom in orbitronics and provide insights into the potential of transition-metal oxides for next-generation orbitronic devices.

cond-mat.mtrl-sci↗

arXiv2025

Giant spin-to-charge conversion in germanium tin epilayers

We report a study of the spin-to-charge current conversion in compressively strained Ge1-xSnx alloy epilayers as a function of the Sn concentration by means of the inverse spin Hall effect (ISHE). The spin current is generated by spin-pumping effect (SPE) from a thin NiFe layer driven into ferromagnetic resonance (FMR). By simultaneously measuring the magnetic damping of the NiFe layer and the ISHE-induced charge current we extract two key spintronics parameters: the spin Hall angle and the effective spin mixing conductance. Our results reveal a giant spin-to-charge conversion and a non-monotonic dependence of the charge current signal on the Sn concentration, consistent with the variation in the magnetic damping observed in FMR. The values of spin Hall angle are comparable to those reported for heavy metals such as Pt and Ta. Furthermore, we show that the spin conductivity at the Au/GeSn interface can be enhanced by tuning the Sn concentration.

cond-mat.mtrl-sci↗

arXiv2024

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

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 $SiO_{2}/Py(5nm)/Pt(4nm)$ structures, the spin pumping signal increased. However, in $SiO_{2}/CuOx(3nm)/Pt(4nm)/Py(5nm)$ 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.

cond-mat.mes-hall↗

arXiv2023

Surface Ferron Excitations in Ferroelectrics and Their Directional Routing

The duality between the electric and magnetic dipoles inspires recent comparisons between ferronics and magnonics. Here we predict surface polarization waves or ``ferrons" in ferroelectric insulators, taking the long-range dipolar interaction into account. We predict properties that are strikingly different from the magnetic counterpart, \textit{i.e.} the surface ``Damon-Eshbach" magnons in ferromagnets. The dipolar interaction pushes the ferron branch with locked circular polarization and momentum to the ionic plasma frequency. The low-frequency modes are on the other hand in-plane polarized normal to their wave vectors. The strong anisotropy of the lower branch renders directional emissions of electric polarization and chiral near fields when activated by a focused laser beam, allowing optical routing in ferroelectric devices.

cond-mat.mes-hall↗