Statistical limits for quantum networks with semiconductor entangled photon sources

TL;DR

This paper investigates the fundamental statistical and device parameter limits for entanglement swapping in semiconductor quantum dot sources, aiming to advance practical quantum networks.

Contribution

It introduces a numerical model to analyze the impact of device variability and tuning on entanglement swapping in quantum dot-based quantum networks.

Findings

Identifies critical device parameters affecting entanglement swapping.

Highlights the importance of exciton fine structure tuning.

Provides a benchmarking framework for device fabrication and tuning effects.

Abstract

Semiconductor quantum dots are promising building blocks for quantum communication applications. Although deterministic, efficient, and coherent emission of entangled photons has been realized, implementing a practical quantum repeater remains outstanding. Here we explore the statistical limits for entanglement swapping with sources of polarization-entangled photons from the commonly used biexciton-exciton cascade. We stress the necessity of tuning the exciton fine structure, and explain why the often observed time evolution of photonic entanglement in quantum dots is not applicable for large quantum networks. We identify the critical, statistically distributed device parameters for entanglement swapping based on two sources. A numerical model for benchmarking the consequences of device fabrication, dynamic tuning techniques, and statistical effects is developed, in order to bring the realization of semiconductor-based quantum networks one step closer to reality.