Self-induced inverse spin Hall effect in permalloy at room temperature

TL;DR

This paper demonstrates the first experimental evidence of self-induced inverse spin Hall effect in permalloy at room temperature, revealing spin-current to charge conversion within a ferromagnetic material due to spin-orbit interaction.

Contribution

It introduces the concept of self-induced ISHE in ferromagnetic materials, specifically permalloy, which was previously unexplored in spintronics research.

Findings

Spin current in permalloy generates a transverse EMF.

Self-induced ISHE occurs due to coupling of spin current and spin-orbit interaction.

Control experiments exclude other effects like spin rectification and Nernst effect.

Abstract

Inverse spin Hall effect (ISHE) allows the conversion of pure spin current into charge current in nonmagnetic materials (NM) due to spin-orbit interaction (SOI). In ferromagnetic materials (FM), SOI is known to contribute to anomalous Hall effect (AHE), anisotropic magnetoresistance (AMR), and other spin-dependent transport phenomena. However, SOI in FM has been ignored in ISHE studies in spintronic devices, and the possibility of "self-induced ISHE" in FM has never been explored until now. In this paper, we demonstrate the experimental verification of ISHE in FM. We found that the spin-pumping-induced spin current in permalloy (Py) film generates a transverse electromotive force (EMF) in the film itself, which results from the coupling of spin current and SOI in Py. The control experiments ruled out spin rectification effect and anomalous Nernst effect as the origin of the EMF.