Comprehensive Demonstration of Spin-Hall Hanle Effects in Epitaxial Pt Thin Films

TL;DR

This paper demonstrates the spin-Hall Hanle effects in epitaxial Pt thin films, revealing their potential to measure spin transport parameters and suggesting their ubiquity in spin-orbit coupled systems.

Contribution

It provides the first comprehensive experimental demonstration of spin-Hall Hanle effects in epitaxial Pt films, enabling direct measurement of key spin transport properties.

Findings

Observation of nonlinear Hall effect due to boundary spin accumulation

SHHE can measure spin diffusion length, spin-Hall angle, and relaxation time

SHHE may be common in spin-orbit coupled materials

Abstract

We demonstrate a nonlinear Hall effect due to the boundary spin accumulation in Pt films grown on Al2O3 substrates. This Hall effect and the previously demonstrated Hanle magnetoresistance provide a complete picture of the spin-precession control of the spin and charge transport at the boundary of a spin-orbit coupled material, which we refer to as spin-Hall Hanle effects (SHHE). We also show that the SHHE can be employed to measure the spin diffusion length, the spin-Hall angle, and the spin relaxation time of heavy metal without the need of magnetic interface or the input from other measurements. The comprehensive demonstration of SHHE in such a simple system suggests they may be ubiquitous and needs to be considered for unravelling the spin and charge transport in more complex thin film structures of spin-orbit coupled materials.