# Gate control of the spin mobility through the modification of the spin-orbit interaction in two-dimensional systems

## TL;DR

This paper demonstrates gate-tunable spin mobility in a two-dimensional electron system by controlling spin-orbit interactions, advancing the development of spin transistors with enhanced control over spin transport.

## Contribution

It introduces a two-subband system with a large Rashba tuning range and provides experimental evidence of spin mobility control via spin-orbit coupling, supported by a random walk model.

## Key findings

- Large Rashba tuning with gate voltage.
- Significant spin mobility anisotropy.
- Agreement between model and experimental data.

## Abstract

Spin drag measurements were performed in a two-dimensional electron system set close to the crossed spin helix regime and coupled by strong intersubband scattering. In a sample with uncommon combination of long spin lifetime and high charge mobility, the drift transport allows us to determine the spin-orbit field and the spin mobility anisotropies. We used a random walk model to describe the system dynamics and found excellent agreement for the Rashba and Dresselhaus couplings. The proposed two-subband system displays a large tuning lever arm for the Rashba constant with gate voltage, which provides a new path towards a spin transistor. Furthermore, the data shows large spin mobility controlled by the spin-orbit constants setting the field along the direction perpendicular to the drift velocity. This work directly reveals the resistance experienced in the transport of a spin-polarized packet as a function of the strength of anisotropic spin-orbit fields.