Optimal spin-charge interconversion in graphene through spin-pseudospin entanglement control

TL;DR

This paper proposes a method to maximize spin-charge interconversion efficiency in graphene by controlling spin-pseudospin entanglement, demonstrating robustness against disorder and potential for advanced spintronic devices.

Contribution

It introduces a novel approach to enhance spin-charge conversion in graphene through spin-pseudospin entanglement control, with theoretical and simulation validation.

Findings

Achieved 100% spin-charge interconversion efficiency via Rashba-Edelstein effect.

Demonstrated robustness of the effect against disorder in simulations.

Identified a disorder-resilient spin Hall effect arising from SOC interplay.

Abstract

The electrical generation of spin signals is of central interest for spintronics, where graphene stands as a relevant platform as its spin-orbit coupling (SOC) is tuned by proximity effects. Here, we propose an enhancement of spin-charge interconversion in graphene by controlling the intraparticle entanglement between the spin and pseudospin degrees of freedom. We demonstrate that, although the spin alone is not conserved in Rashba-Dirac systems, a combined spin-pseudospin operator is conserved. This conserved quantity represents the interconversion between pure spin and pseudospin textures to a spin-pseudospin entangled structure, where Kane-Mele SOC tunes this balance. By these means, we achieve spin-charge interconversion of 100\% efficiency via the Rashba-Edelstein effect. Quantum transport simulations in disordered micron-size systems demonstrate the robustness of this effect, and also reveal a disorder resilient spin Hall effect generated by the interplay between Rashba and Kane-Mele SOC. Our findings propose a platform for maximally efficient spin-charge interconversion, and establish spin-pseudospin correlations as a mechanism to tailor spintronic devices.