Optical orientation of spins in GaAs:Mn/AlGaAs quantum wells via impurity-to-band excitation

TL;DR

This study demonstrates control over spin polarization in Mn-doped GaAs/AlGaAs quantum wells through impurity-to-band optical excitation, revealing a sign inversion of luminescence polarization and altered hole g factors due to quantum confinement.

Contribution

It provides new insights into spin control mechanisms and magnetic property modifications in doped semiconductor quantum wells using optical methods.

Findings

Spin polarization can be controlled via impurity-to-band excitation.

Luminescence polarization sign can invert with pump power.

Hole g factor is significantly affected by quantum confinement.

Abstract

The paper reports optical orientation experiments performed in the narrow GaAs/AlGaAs quantum wells doped with Mn. We experimentally demonstrate a control over the spin polarization by means of the optical orientation via the impurity-to-band excitation and observe a sign inversion of the luminescence polarization depending on the pump power. The g factor of a hole localized on the Mn acceptor in the quantum well was also found to be considerably modified from its bulk value due to the quantum confinement effect. This finding shows the importance of the local environment on magnetic properties of the dopants in semiconductor nanostructures.