Violation of Bell's inequality with quantum-dot single-photon sources

TL;DR

This paper explores how to achieve a loophole-free violation of Bell's inequality using quantum-dot single-photon sources, analyzing real-world imperfections and their impact on experimental feasibility for quantum communication.

Contribution

It provides a detailed analysis of implementing loophole-free Bell tests with quantum-dot sources, including performance benchmarks and requirements for device-independent quantum key distribution.

Findings

Experimental realizations are within reach based on current quantum dot technology.

Post-selected protocols can relax source efficiency requirements.

Key imperfections like photon indistinguishability impact violation feasibility.

Abstract

We investigate the possibility of realizing a loophole-free violation of Bell's inequality using deterministic single-photon sources. We provide a detailed analysis of a scheme to achieve such violations over long distances with immediate extensions to device-independent quantum key distribution. We investigate the effect of key experimental imperfections that are unavoidable in real-world single-photon sources including the finite degree of photon indistinguishability, single-photon purity, and the overall source efficiency. We benchmark the performance requirements to state-of-the-art deterministic single-photon sources based on quantum dots in photonic nanostructures and find that experimental realizations appear to be within reach. We also evaluate the requirements for a post-selected version of the protocol, which relaxes the demanding requirements with respect to the source efficiency.