aiqbench analysis
This research addresses a fundamental limitation in quantum dot emitters where the second photon in a cascade reduces interference visibility due to temporal mismatch at beam splitters. By demonstrating that post-emission synchronization can recover maximum interference, the study paves the way for more reliable entangled photon sources essential for scalable quantum networks. The findings suggest that deterministic quantum memories could effectively overcome this specific physical constraint in future architectures.
Overcoming the Hong-Ou-Mandel interference limitation for the second photon from a two-photon cascade
arXiv:2609.24858v1 Announce Type: new Abstract: Quantum emitters such as semiconductor quantum dots can provide entangled photon pairs emitting from a system of cascaded states. However, the resulting temporal correlation between the two photons from the three-level ladder system has been shown to set a limit on the achievable two-photon interference. In this work, we show that such limitation, for photons emitted by the second transition, is only due to reduced temporal overlap at the interference beam splitter. We investigate this theoretically and experimentally by determining time-resolved four-photon coincidences between two successively emitted photon pairs. Post-emission synchronization shows the recovery of maximum interference visibility; in prospective quantum networks this could be achieved via deterministic quantum memories.
Authors:Raphael Joos, Michal Vyvlecka, Tim Strobel, Benjamin Breiholz, Furkan Aglarci, Ponraj Vijayan, Hans-Georg Babin, Arne Ludwig, Michael Jetter, Simone L. Portalupi, Peter Michler
Abstract:Quantum emitters such as semiconductor quantum dots can provide entangled photon pairs emitting from a system of cascaded states. However, the resulting temporal correlation between the two photons from the three-level ladder system has been shown to set a limit on the achievable two-photon interference. In this work, we show that such limitation, for photons emitted by the second transition, is only due to reduced temporal overlap at the interference beam splitter. We investigate this theoretically and experimentally by determining time-resolved four-photon coincidences between two successively emitted photon pairs. Post-emission synchronization shows the recovery of maximum interference visibility; in prospective quantum networks this could be achieved via deterministic quantum memories.
Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Optics (physics.optics)
arXiv:2609.24858 [quant-ph]
(or arXiv:2609.24858v1 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2609.24858 arXiv-issued DOI via DataCite (pending registration)
Full text under the publisher's open licence · 158 words
Related coverage

Researchers Attain 99% Indistinguishable Photons from Chips
Quantum Zeitgeist · Sep 17, 2026

Atomic Clocks Enable Link-Free Quantum Network Synchronisation
Quantum Zeitgeist · Jun 15, 2026

Researchers Build First Fully Connected Quantum Network with Microcombs
Quantum Zeitgeist · Aug 3, 2026

Single-Photon Sources Hit 88% Indistinguishability, Enabling Scalable Qubits
Quantum Zeitgeist · May 31, 2026