Spin Control of Drifting Electrons using Local Nuclear Polarization in Ferromagnet/Semiconductor Heterostructures

TL;DR

This paper presents a method to control the spin rotation of drifting electrons in a GaAs channel by locally manipulating nuclear polarization using ferromagnetic interfaces, enabling coherent spin rotations exceeding 4 pi radians.

Contribution

It introduces a novel approach to locally control electron spin rotation in semiconductors via nuclear polarization modulated by ferromagnetic proximity effects.

Findings

Achieved coherent spin rotations exceeding 4 pi radians during electron transport.

Controlled the effective nuclear magnetic field optically and electrically.

Demonstrated modulation of electron spin dynamics through local nuclear polarization.

Abstract

We demonstrate methods to locally control the spin rotation of moving electrons in a GaAs channel. The Larmor frequency of optically-injected spins is modulated when the spins are dragged through a region of spin-polarized nuclei created at a MnAs/GaAs interface. The effective field created by the nuclei is controlled either optically or electrically using the ferromagnetic proximity polarization effect. Spin rotation is also tuned by controlling the carrier traverse time through the polarized region. We demonstrate coherent spin rotations exceeding 4 pi radians during transport.