Spin light emitting diode based on exciton fine structure tuning in quantum dots

TL;DR

This paper introduces a quantum dot-based light emitting diode that can produce fully circularly polarized light by tuning exciton fine structure with magnetic fields and hyperfine interactions, enabling compact, efficient, and deterministic polarized photon sources.

Contribution

It presents a novel design for a quantum dot LED that achieves high polarization control and single-photon generation using magnetic tuning and hyperfine interactions.

Findings

Circular polarization degree can reach 100%.

Device operates under small magnetic fields (~milliteslas).

Compatible with micropillar cavities for single-photon emission.

Abstract

We propose a concept of quantum dot based light emitting diode that produces circularly polarized light due to the tuning of the exciton fine structure by magnetic field and electron nuclear hyperfine interaction. The device operates under injection of electrons and holes from nonmagnetic contacts in a small field of the order of milliteslas. Its size can be parametrically smaller than the light wavelength, and circular polarization degree of electroluminescence can reach 100%. The proposed concept is compatible with the micropillar cavities, which allows for the deterministic electrical generation of single circularly polarized photons.