Self-induced inverse spin Hall effect in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ films

TL;DR

This paper demonstrates that La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ films can generate a significant self-induced inverse spin Hall voltage during spin pumping, revealing efficient spin-charge conversion in ferromagnetic manganite films.

Contribution

The study shows for the first time that ferromagnetic manganite films exhibit a self-induced inverse spin Hall effect during spin pumping, combining experimental measurements with theoretical calculations.

Findings

Self-induced inverse spin Hall voltage of 1.86 μV observed in LSMO films.

Spin to charge conversion efficiency aligns with theoretical predictions.

Ferromagnetic manganite films can generate spin currents via inverse spin Hall effect.

Abstract

The efficient generation of spin currents and spin torques via spin-orbit coupling is an important goal of spintronics research. One crucial metric for spin current generation is the spin Hall angle, which is the ratio of the spin Hall current to the transversely flowing charge current. A typical approach to measure the spin Hall angle in nonmagnetic materials is to generate spin currents via spin pumping in an adjacent ferromagnetic layer and measure the transverse voltage from the inverse spin Hall effect in the nonmagnetic layer. However, given that the spin Hall effect also occurs in ferromagnets, single ferromagnetic layers could generate a self-induced transverse voltage during spin pumping as well. Here we show that manganite based La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ (LSMO) films deposited by pulsed laser deposition exhibit a significant self-induced inverse spin Hall voltage while undergoing spin pumping. We observe efficient spin to charge conversion in the LSMO films via the inverse spin Hall effect. A spin pumping voltage of 1.86 $\mu$V is observed in the LSMO (12 nm) film. Using density functional theory and the Kubo formalism, we calculate the intrinsic spin current conductivities of these films and show that they are in reasonable agreement with the experimental measurements.