Spin-current-related magnetoresistance in epitaxial Pt/Co bilayers in the presence of spin Hall effect and Rashba-Edelstein effect

TL;DR

This paper models spin-current-related magnetoresistance in epitaxial Pt/Co bilayers, highlighting the roles of bulk spin Hall and interfacial Rashba-Edelstein effects, and provides quantitative parameters consistent with theoretical and previous experimental findings.

Contribution

It introduces a comprehensive drift-diffusion model that incorporates both bulk and interfacial effects to analyze magnetoresistance in epitaxial Pt/Co bilayers.

Findings

Rashba parameter ~1e-11 eV m consistent with theory

Interfacial REE thickness of several angstroms

Both bulk and interfacial effects are essential for analysis

Abstract

We analyze the experimentally obtained spin-current-related magnetoresistance in epitaxial Pt/Co bilayers by using a drift-diffusion model that incorporates both bulk spin Hall effect and interfacial Rashba-Edelstein effect (REE). The magnetoresistance analysis yields, for the Pt/Co interface, a temperature-independent Rashba parameter in the order of 1e-11 eV m that agrees with theoretical calculations, along with an effective interfacial REE thickness of several angstroms which is in overall consistency with our previous spin-orbit torque analysis. In particular, our results suggest that both bulk and interface charge-spin current inter-conversions need to be taken into account for the spin-current-related magnetoresistance analysis in highly-conductive magnetic hetero-structures such as the epitaxial Pt/Co bilayers.