Experimental certification of a robust contextuality witness and quantum randomness
Phys. Rev. A 113, 012423 – Published 13 January, 2026
DOI: https://doi.org/10.1103/ch2b-g4zk
Abstract
Contextuality, a fundamental feature distinguishing quantum mechanics from classical theories, has emerged as a vital resource for quantum advantage. While contextuality is well established theoretically, its experimental demonstrations via optimal two-state discrimination remain scarce. Here, we report an experimental study employing a two-path Sagnac interferometer to implement and characterize a contextuality witness. Our results reveal a robust contextuality witness in both noiseless and depolarizing noise cases. Remarkably, controlled introduction of inconclusive rates dynamically enhances noise resilience, revealing a tunable contextuality witness through adjustment of inconclusive rates. Furthermore, we verify quantum randomness under different noise conditions, ensuring robust min-entropy extraction with optimal state discrimination performance. These experimental results advance both fundamental understanding of contextuality as a quantum resource and its practical application in noise-resilient quantum information processing, facilitating the development of more reliable quantum technologies.
