Fig. 5: Effect of additional loss after PSA on state tomography.
From: Broadband generation and tomography of non-Gaussian states for ultra-fast optical quantum processors
a Dependence of Wigner negativities on additional loss. b Dependence between the additional loss and the fidelity to state without additional loss. We also plot the theoretical prediction for the case where same additional loss is added, but we do not use the second OPA as an amplifier. The theoretical lines for the both with and without PSA cases are plotted using the experimental parameters of the setup. The insets in a show the quadrature distributions at antisqueezing phase for each loss. Although the dip near 0 becomes less resolvable with more loss, the non-Gaussian feature remains even with additional loss of 20 dB. The error bars show ± 1 standard deviation.
