Two-dimensional imaging of the spin-orbit effective magnetic field

TL;DR

This study spatially maps the spin-orbit effective magnetic field in a quantum well by measuring local electron spin precession, revealing how electric fields induce Rashba and Dresselhaus effects with good simulation agreement.

Contribution

It provides the first spatially resolved measurements of spin-orbit fields in a quantum well under electric field control.

Findings

Good agreement between experimental data and simulations

Electric fields induce measurable Rashba and Dresselhaus fields

Spatially resolved spin-precession measurements are feasible

Abstract

We report on spatially resolved measurements of the spin-orbit effective magnetic field in a GaAs/InGaAs quantum-well. Biased gate electrodes lead to an electric-field distribution in which the quantum-well electrons move according to the local orientation and magnitude of the electric field. This motion induces Rashba and Dresselhaus effective magnetic fields. The projection of the sum of these fields onto an external magnetic field is monitored locally by measuring the electron spin-precession frequency using time-resolved Faraday rotation. A comparison with simulations shows good agreement with the experimental data.