Fine-structure splitting reduction of ionized impurity bound exciton in quantum dot

TL;DR

This paper investigates how off-center ionized impurities and external electric fields can significantly reduce the fine-structure splitting of excitons in quantum dots, with implications for quantum photonic devices.

Contribution

It demonstrates a method to reduce fine-structure splitting in quantum dots using off-center impurities and electric fields, aiding quantum entangled-photon source design.

Findings

Fine-structure splitting can be largely reduced by off-center ionized impurities.

External electric fields induce anomalous Stark shifts in the ground-state energy.

The scheme offers a potential approach for quantum dot-based entangled-photon sources.

Abstract

The ground-state energy and fine-structure splitting of ionized shallow donor impurity-exciton complex in quantum dots are investigated. It is found that fine-structure splitting could be largely reduced by the off-center ionized impurities since the anisotropic shape of exciton envelope function is significantly changed. Anomalous Stark shifts of the ground-state energy and efficient tuning of the fine-structure splitting by the external electric field due to the local electric field produced by the ionized impurities are discussed. The scheme may be useful for the design of the quantum dots-based entangled-photon source.