We experimentally test new ways to detect the nonclassicality of a state from correlations among different phase-space distributions. See our latest PRL paper.
Many different methods exist to verify the quantumness of a state. However, the certication of nonclassical features in realistic, complex, and noisy systems is still a challenging task. Here we present the first experimental implementation of phase-space distribution inequalities to certify the nonclassicality of single-photon-added thermal light states in a wide range of parameters. We find that nonclassical behavior can be reliably certified in regions where many other methods fail.