On-Chip Semi-Device-Independent Quantum Random Number Generator Exploiting Contextuality

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 10σ, unambiguously confirming non-classical behavior. From this violation, we certify a conditional min-entropy per experimental round of H_min ¼ 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 toward semi-device-independent quantum random number generators compatible with practical integrated photonic quantum networks.