Characterization of Quantumness of non-Gaussian states under the influence of Gaussian channel

TL;DR

This paper investigates how Gaussian noise affects the non-Gaussian quantum states, revealing that photon addition offers more robustness than subtraction and that nonclassicality can be enhanced through photon addition.

Contribution

It provides a detailed analysis of the impact of Gaussian channels on non-Gaussian states, highlighting the robustness of photon addition and conditions for nonclassicality preservation.

Findings

Photon addition is more robust than photon subtraction under Gaussian noise.

The noise threshold depends on thermal photons and squeezing parameters.

Adding photons can enhance nonclassicality of thermal states.

Abstract

The impact of a noisy Gaussian channel on a wide range of non-Gaussian input states is studied in this work. The nonclassical nature of the states, both input and output, is developed by studying the corresponding photon statistics and quasi-probability distributions. It is found that photon addition has more robust quantum mechanical properties as compared to the photon subtraction case. The threshold value of the noise parameter corresponding to the transition from partial negative (W and P ) and zero (Q) to completely positive definite, at the center of phase space, depends not only on the average number of thermal photons in the state, but also on the squeezing parameter. In addition it is observed that the nonclassicality of the kth-number filtrated thermal state could be further enhanced by adding photon(s).