Spin and orbital-to-charge conversion in noncentrosymmetric materials: Hall versus Rashba-Edelstein effects

TL;DR

This paper develops a macroscopic formalism to analyze spin and orbital to charge conversion in noncentrosymmetric materials, highlighting the dominance of the Rashba-Edelstein effect over Hall effects in charge current generation.

Contribution

It introduces a general macroscopic formalism for spin and orbital-to-charge conversion, validated through a case study on ferroelectric GeTe, revealing a smaller Rashba parameter than previously reported.

Findings

Charge current mainly driven by Rashba-Edelstein effect in GeTe.

Effective Rashba parameter smaller than earlier estimates.

Formalism based on macroscopic observables applicable to nonmagnetic materials.

Abstract

We investigate spin- and orbital-to-charge conversion phenomena in nonmagnetic materials with broken inversion symmetry, treating the contributions from the Hall effect and the Rashba-Edelstein effect on an equal footing. We develop a general formalism for this interconversion based solely on macroscopic observables. The theory is validated through a case study of ferroelectric GeTe, where we find that the effective Rashba parameter obtained is smaller than previously reported values for the same material. Incorporating these parameters into a drift-diffusion model, we show that the generated charge current is primarily governed by the Rashba-Edelstein effect, rather than by the spin or orbital Hall effects.