Detecting nonclassicality and non-Gaussianity of a coherent superposed quantum state

Abstract

In this paper, we investigate the nonclassicality and non-Gaussianity of a coherent superposed quantum state (CSQS) which is obtained by applying a coherent superposition of field annihilation ($a$) and creation ($a^\dagger$) operators, $N(ta+ra^\dagger)$ to a classical coherent state $|\alpha\rangle$, where $t$ and $r$ are scalars with $t^2+r^2=1$. Such an operation, when applied on states having classical characters, introduces strong nonclassicality. We use different criteria to check the nonclassicality and non-Gaussianity of the considered quantum state. We first compute the Wigner function of CSQS. To study the nonclassicality of the considered state we further use (i) linear entropy (LE) (ii) Wigner logarithmic negativity (WLN) and (iii) skew information based measure. Relative entropy based measure is considered to analyze the variation in non-Gaussianity of CSQS. Finally, the dynamics of the Wigner function evolving under the photon loss channel is addressed to probe the effect of noise on nonclassicality as well as non-Gaussianity of CSQS.