Coalescence of Single Photons Emitted by Disparate Single Photon Sources: The Example of InAs Quantum Dots and Parametric Down-Conversion Sources

TL;DR

This paper demonstrates how photons from different sources, specifically quantum dots and parametric down-conversion, can be made indistinguishable through manipulation, enabling their use in scalable quantum networks.

Contribution

It introduces a method to achieve indistinguishability between photons from dissimilar sources, overcoming fundamental differences for quantum network integration.

Findings

Measured two-photon coalescence probability of 16%.

Temporal filtering increases indistinguishability to 61%.

Technique enables connecting different quantum elements.

Abstract

Single photons produced by fundamentally dissimilar physical processes will in general not be indistinguishable. We show how photons produced from a quantum dot and by parametric down-conversion in a nonlinear crystal can be manipulated to be indistinguishable. The measured two-photon coalescence probability is 16%, and is limited by quantum-dot decoherence. Temporal filtering to the quantum dot coherence time and accounting for detector time response increases this to 61% while retaining 25% of the events. This technique can connect different elements in a scalable quantum network.