Single scatterings in single artificial atoms: Quantum coherence and entanglement

TL;DR

This paper investigates quantum coherence and entanglement in single semiconductor quantum dots through quantum-jump analysis, revealing oscillatory photon correlations and spin entanglement transfer mechanisms.

Contribution

It provides a detailed theoretical study of two-photon correlations and spin entanglement transfer in single quantum dots, highlighting effects of fine-structure splitting and tunneling.

Findings

Oscillatory behavior of two-photon correlations due to fine-structure splitting.

Transfer of quantum properties from excitons to electron spins via tunneling.

Identification of disentanglement mechanisms in quantum dot systems.

Abstract

We employ the quantum-jump approach to study single scatterings in single semiconductor quantum dots. Two prototypical situations are investigated. First, we analyze two-photon emissions from the cascade biexciton decay of a dot where the single-exciton states exhibit a fine-structure splitting. We show that this splitting results for appropriately chosen polarization filters in an oscillatory behavior of two-photon correlations, and carefully examine the proper theoretical description of the underlying scattering processes. Secondly, we analyze the decay of a single-electron charged exciton in a quantum dot embedded in a field effect structure. We show how the quantum properties of the charged exciton are transferred through tunneling and relaxation to the spin entanglement between electrons in the dot and contact, and identify the pertinent disentanglement mechanisms.