Nonclassicality of photon-added squeezed vacuum and its decoherence in thermal environment

TL;DR

This paper investigates the nonclassical properties of photon-added squeezed vacuum states, analyzing their sub-Poissonian statistics and Wigner function negativity, and studies how these properties decay in a thermal environment over time.

Contribution

It provides explicit formulas for the normalization and Wigner function of photon-added squeezed vacuum states and analyzes their nonclassicality and decoherence in thermal channels.

Findings

Existence of an upper bound for squeezing parameter r for sub-Poissonian statistics.

Explicit analytical expressions for the Wigner function and its evolution in thermal environments.

Identification of a threshold decay time for the loss of nonclassicality in PASV states.

Abstract

We study the nonclassicality of photon-added squeezed vacuum (PASV) and its decoherence in thermal environment in terms of the sub-Poissonian statistics and the negativity of Wigner function (WF). By converting the PASV to a squeezed Hermite polynomial excitation state, we derive a compact expression for the normalization factor of m-PASV, which is an m-order Legendre polynomial of squeezing parameter r. We also derive the explicit expression of WF of m-PASV and find the negative region of WF in phase space. We show that there is an upper bound value of r for this state to exhibit sub-Poissonian statistics increasing as m increases. Then we derive the explicit analytical expression of time evolution of WF of m-PASV in the thermal channel and discuss the loss of nonclassicality using the negativity of WF. The threshold value of decay time is presented for the single PASV.