Current-controlled Spin Precession of Quasi-Stationary Electrons in a Cubic Spin-Orbit Field

TL;DR

This study demonstrates current-controlled spin precession in a 2D electron gas, revealing a linear relationship between drift velocity and precession frequency driven by cubic Dresselhaus spin-orbit interaction, without external magnetic fields.

Contribution

It provides the first direct measurement of spin precession caused by cubic Dresselhaus interaction in a quasi-stationary electron system.

Findings

Precession frequency depends linearly on drift velocity.

Precession occurs without external magnetic fields.

Drift causes a spin precession angle twice that of diffusion.

Abstract

Space- and time-resolved measurements of spin drift and diffusion are performed on a GaAs-hosted two-dimensional electron gas. For spins where forward drift is compensated by backward diffusion, we find a precession frequency in absence of an external magnetic field. The frequency depends linearly on the drift velocity and is explained by the cubic Dresselhaus spin-orbit interaction, for which drift leads to a spin precession angle twice that of spins that diffuse the same distance.