Certification of Non-Gaussian States with Operational Measurements
Ulysse Chabaud, Ganaël Roeland, Mattia Walschaers, Frédéric Grosshans, Valentina Parigi, Damian Markham, Nicolas Treps · PRX Quantum · 2021
We derive a theoretical framework for the experimental certification of non-Gaussian features of quantum states using double homodyne detection.We rank experimental non-Gaussian states according to the recently defined stellar hierarchy and we propose practical Wigner negativity witnesses.We simulate various use-cases ranging from fidelity estimation to witnessing Wigner negativity.Moreover, we extend results on the robustness of the stellar hierarchy of non-Gaussian states.Our results illustrate the usefulness of double homodyne detection as a practical measurement scheme for retrieving information about continuous-variable quantum states, and show that certification of high-order non-Gaussian features can be carried out experimentally with current technology.