Spin-dependent (inverse) spin Hall effect in Co$_{60}$Fe$_{20}$B$_{20}$

TL;DR

This study demonstrates a spin-dependent inverse spin Hall effect in a ferromagnetic alloy, showing how magnetization orientation modulates spin current signals, with implications for spintronic device control.

Contribution

It reports the first observation of a spin-dependent inverse spin Hall effect in Co$_{60}$Fe$_{20}$B$_{20}$, highlighting its modulation by magnetization direction and confirming an intrinsic electronic origin.

Findings

Signal amplitude modulated by magnetization direction.

Intrinsic electronic origin confirmed by sample design.

Complete suppression of magnonic coupling in the structure.

Abstract

In ferromagnetic metals, the interconversion of spin and charge currents via the spin Hall effect and its inverse can depend on the angle between the ferromagnets magnetization and the spin current polarization direction. Here, such a spin-dependent (inverse) spin Hall effect is found in the ferromagnetic alloy Co$_{60}$Fe$_{20}$B$_{20}$. In a nonlocal magnon transport experiment, Co$_{60}$Fe$_{20}$B$_{20}$ is used to both excite and detect magnonic spin currents flowing in the ferrimagnetic insulator Y$_{3}$Fe$_{5}$O$_{12}$. We find that the signal amplitude is significantly modulated by tuning the direction of the Co$_{60}$Fe$_{20}$B$_{20}$ magnetization. We design a sample structure that completely prevents direct magnonic coupling between the ferromagnets. Thus, we can identify unambiguously an intrinsic electronic origin of the observed effect.