Optimized stray-field-induced enhancement of the electron spin precession by buried Fe gates

TL;DR

This study demonstrates that buried Fe gates can significantly enhance electron spin precession in quantum wells through magnetic stray fields, with the effect tunable by gate spacing, advancing spintronic device control.

Contribution

It introduces a novel fabrication method positioning Fe gates in-plane with quantum wells, significantly increasing stray-field effects compared to top-gated structures.

Findings

Stray fields from buried Fe gates modify spin precession frequency.

Reducing gate gap increases stray-field-induced precession.

Inhomogeneous stray fields cause additional spin dephasing.

Abstract

The magnetic stray field from Fe gates is used to modify the spin precession frequency of InGaAs/GaAs quantum-well electrons in an external magnetic field. By using an etching process to position the gates directly in the plane of the quantum well, the stray-field influence on the spin precession increases significantly compared with results from previous studies with top-gated structures. In line with numerical simulations, the stray-field-induced precession frequency increases as the gap between the ferromagnetic gates is reduced. The inhomogeneous stray field leads to additional spin dephasing.