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arXiv · 2610.03351

Quantum Key Distribution with Entanglement-Swapped Photons from a Quantum Emitter

Michele B. Rota·Francesco Basso Basset·Alessandro Laneve·Francesco Salusti·Nicolas Claro-Rodriguez·Giuseppe Ronco·Mattia Beccaceci·Tobias M. Krieger·Quirin Buchinger·Saimon F. Covre da Silva·Sandra Stroj·Mariia Gumberidze·Vladyslav Usenko·Sven Höfling·Tobias Huber-Loyola·Mario A. Usuga Castaneda·Armando Rastelli·Klaus D. Jöns·Rinaldo Trotta
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Abstract

Quantum key distribution (QKD) is a fundamental functionality of quantum networks. Extending its range requires quantum repeaters, a technology still under development and not yet demonstrated in combination with quantum cryptographic protocols. Here, we address the elementary operation of a viable quantum repeater scheme by evaluating whether correlated photons distributed via entanglement swapping can support secret key distribution. We employ a state-of-the-art deterministic photon source based on a strain-tuned GaAs quantum dot embedded in a photonic cavity and implement a source-independent QKD protocol between two nodes using entanglement-swapped photons. We benchmark the system and present how high-resolution temporal post-selection can enable secure key exchange, with further rate improvements expected through realistic device and protocol optimizations. Due to its compatibility with a wide range of quantum memory platforms, our approach represents a significant step towards long-distance quantum-safe communication.

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Michele B. Rota, Francesco Basso Basset, Alessandro Laneve, Francesco Salusti, Nicolas Claro-Rodriguez, Giuseppe Ronco, Mattia Beccaceci, Tobias M. Krieger, Quirin Buchinger, Saimon F. Covre da Silva, Sandra Stroj, Mariia Gumberidze, Vladyslav Usenko, Sven Höfling, Tobias Huber-Loyola, Mario A. Usuga Castaneda, Armando Rastelli, Klaus D. Jöns, Rinaldo Trotta. 2026-10-02. Quantum Key Distribution with Entanglement-Swapped Photons from a Quantum Emitter. https://doi.org/10.1103/68f1-cjfk

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