# Electric control of spin transport in GaAs (111) quantum wells

## TL;DR

This study demonstrates that applying an electric field to GaAs (111) quantum wells enables long-distance transport of spin-polarized electrons by compensating intrinsic spin-orbit effects, with results supported by a drift-diffusion model.

## Contribution

It shows electric control of spin transport length in GaAs (111) quantum wells through SO-field compensation, a novel approach for spintronic device applications.

## Key findings

- Spin transport distances exceed 10 μm with electric field application.
- Long spin transport is due to compensation of intrinsic SO interaction.
- Model confirms drift-diffusion of spin-polarized carriers under weak SO interaction.

## Abstract

We show by spatially and time-resolved photoluminescence that the application of an electric field transverse to the plane of an intrinsic GaAs (111) quantum well (QW) allows the transport of photogenerated electron spins polarized along the direction perpendicular to the QW plane over distances exceeding 10~$\mu$m. We attribute the long spin transport lengths to the compensation of the in-plane effective magnetic field related to the intrinsic spin-orbit (SO) interaction by means of the electrically generated SO-field. Away from SO-compensation, the precession of the spin vector around the SO-field decreases the out-of-plane polarization of the spin ensemble as the electrons move away from the laser generation spot. The results are reproduced by a model for two-dimensional drift-diffusion of spin polarized charge carriers under weak SO-interaction.