Quantum superposition of high-dimensional states enables both computational speed-up and security in cryptographic protocols. However, the exponential complexity of tomographic processes makes certification of these properties a challenging task. In this work, we experimentally certify coherence witnesses tailored for quantum systems of increasing dimension, using pairwise overlap measurements enabled by a six-mode universal photonic processor fabricated with a femtosecond laser writing technology. In particular, we show the effectiveness of the proposed coherence and dimension witnesses for qudits of dimensions up to 5. We also demonstrate advantage in a quantum interrogation task, and show it is fueled by quantum contextuality. Our experimental results testify to the efficiency of this novel approach for the certification of quantum properties in programmable integrated photonic platforms
@article{arxiv.2311.03266,
title = {Experimental certification of contextuality, coherence and dimension in a programmable universal photonic processor},
author = {Taira Giordani and Rafael Wagner and Chiara Esposito and Anita Camillini and Francesco Hoch and Gonzalo Carvacho and Ciro Pentangelo and Francesco Ceccarelli and Simone Piacentini and Andrea Crespi and Nicolò Spagnolo and Roberto Osellame and Ernesto F. Galvão and Fabio Sciarrino},
journal= {arXiv preprint arXiv:2311.03266},
year = {2023}
}