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

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. Our work redefines the spin- and orbit-to-charge interconversion coefficients in terms of directly measurable observables, encouraging the community to revisit these processes in other quantum materials lacking inversion symmetry.