We reported on experimental verification of quantum non-Gaussianity of a heralded single photon state with positive Wigner function [Phys. Rev. Lett. 107, 213602 (2011)]. We unambiguously demonstrated that the generated state cannot be expressed as a mixture of Gaussian states. A sufficient information to witness the quantum non-Gaussianity was obtained from a standard photon anti-correlation measurement. Our approach is based on the non-Gaussianity criterion devised by Radim Filip and Ladislav Mišta [Phys. Rev. Lett. 106, 200401 (2011)].
Experimental test of the quantum non-Gaussian character of a heralded single-photon state