Linear polarization of the photoluminescence of quantum wells

TL;DR

This paper investigates the linear polarization of photoluminescence in (Cd,Mn)Te quantum wells under magnetic fields, combining experimental measurements with a theoretical model based on in-plane deformation effects.

Contribution

It provides a combined experimental and theoretical analysis of magnetic-field induced linear polarization in quantum wells, highlighting the role of in-plane deformation on valence band states.

Findings

Theoretical model agrees with experimental data.

In-plane deformation influences valence band spin anisotropy.

Results applicable to non-magnetic quantum wells and quantum dots.

Abstract

The degree and orientation of the magnetic-field induced linear polarization of the photoluminescence from a wide range of heterostructures containing (Cd,Mn)Te quantum wells between (Cd,Mn,Mg)Te barriers has been studied as a function of detection photon energy, applied magnetic field strength and orientation in the quantum well plane. A theoretical description of this effect in terms of an in-plane deformation acting on the valence band states is presented and is verified by comparison with the experimental data. We attempted to identify clues to the microscopic origin of the valence band spin anisotropy and to the mechanisms which actually determine the linear polarization of the PL in the quantum wells subject to the in-plane magnetic field. The conclusions of the present paper apply in full measure to non-magnetic QWs as well as ensembles of disk-like QDs with shape and/or strain anisotropy.