Edge spin accumulation: spin Hall effect without bulk spin current

TL;DR

This paper demonstrates that in a 2D electron gas with Rashba spin-orbit interaction, spin accumulation can occur at the edges without bulk spin currents, driven by wave interference effects.

Contribution

It reveals the edge spin Hall effect can exist independently of bulk spin currents, using a Boltzmann equation approach in the collisional regime.

Findings

Edge spin accumulation occurs without bulk spin currents.

Interference of electron waves at boundaries causes spin accumulation.

The effect is demonstrated in a 2D electron gas with Rashba interaction.

Abstract

Spin accumulation in a 2D electron gas with Rashba spin-orbit interaction subject to an electric field can take place without bulk spin currents (edge spin Hall effect). This is demonstrated for the collisional regime using the non-equilibrium distribution function determined from the standard Boltzmann equation. Spin accumulation originates from interference of incident and reflected electron waves at the sample boundary.