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arXiv · 2601.08392

On-chip semi-device-independent quantum random number generator exploiting contextuality

Maddalena Genzini·Caterina Vigliar·Mujtaba Zahidy·Hamid Tebyanian·Andrzej Gajda·Klaus Petermann·Lars Zimmermann·Davide Bacco·Francesco Da Ros
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Abstract

We present a semi-device-independent quantum random number generator (QRNG) based on the violation of a contextuality inequality, implemented by the integration of two silicon photonic chips. Our system combines a heralded single-photon source with a reconfigurable interferometric mesh to implement qutrit state preparation, transformations, and measurements suitable for testing a KCBS contextuality inequality. This architecture enables the generation of random numbers from the intrinsic randomness of single-photon interference in a complex optical network, while simultaneously allowing a quantitative certification of their security without requiring entanglement. We observe a contextuality violation exceeding the classical bound by more than 10{\sigma}, unambiguously confirming non-classical behavior. From this violation, we certify a conditional min-entropy per experimental round of Hmin = 0.077 +- 0.002, derived via a tailored semidefinite-programming-based security analysis. Each measurement outcome therefore contains at least 0.077 +- 0.002 bits of extractable genuine randomness, corresponding to an asymptotic generation rate of 21.7 +- 0.5 bits/s. These results establish a viable route towards general-purpose, untrusted quantum random number generators compatible with practical integrated photonic quantum networks.

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Maddalena Genzini, Caterina Vigliar, Mujtaba Zahidy, Hamid Tebyanian, Andrzej Gajda, Klaus Petermann, Lars Zimmermann, Davide Bacco, Francesco Da Ros. 2026-01-13. On-chip semi-device-independent quantum random number generator exploiting contextuality. https://doi.org/10.1103/62lv-gmsz

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