Highly efficient heralding of entangled single photons

TL;DR

This paper demonstrates a highly efficient heralded single-photon source with 83% efficiency, confirming high-quality entanglement suitable for advanced quantum communication protocols.

Contribution

The work presents an experimental realization of a heralded single-photon source with unprecedented efficiency and entanglement quality using spontaneous parametric down-conversion and fiber-coupled sensors.

Findings

Heralding efficiency of 83% without correction

Violation of Bell inequality confirming entanglement

Suitable for device-independent quantum key distribution

Abstract

Single photons are an important prerequisite for a broad spectrum of quantum optical applications. We experimentally demonstrate a heralded single-photon source based on spontaneous parametric down-conversion in collinear bulk optics, and fiber-coupled bolometric transition-edge sensors. Without correcting for background, losses, or detection inefficiencies, we measure an overall heralding efficiency of 83 %. By violating a Bell inequality, we confirm the single-photon character and high-quality entanglement of our heralded single photons which, in combination with the high heralding efficiency, are a necessary ingredient for advanced quantum communication protocols such as one-sided device-independent quantum key distribution.