Nonclassicality and decoherence of photon-added squeezed thermal state in thermal environment

TL;DR

This paper provides a theoretical analysis of the nonclassical properties and decoherence effects of photon-added squeezed thermal states in a thermal environment, revealing their robustness and specific quantum features.

Contribution

It introduces a compact expression for the normalization factor of photon-added squeezed thermal states using Legendre polynomials and analyzes their nonclassicality and decoherence behavior.

Findings

Wigner function of single photon-added STS is always negative at the phase space center.

Decoherence threshold time is longer for single photon-added STS than for photon-subtracted states.

Photon-added states exhibit robust nonclassical features under thermal decoherence.

Abstract

Theoretical analysis is given of nonclassicality and decoherence of the field states generated by adding any number of photons to the squeezed thermal state (STS). Based on the fact that the squeezed number state can be considered as a single-variable Hermite polynomial excited state, the compact expression of the normalization factor is derived, a Legendre polynomial. The nonclassicality is investigated by exploring the sub-Poissonian and negative Wigner function (WF). The results show that the WF of single photon-added STS (PASTS) always has negative values at the phase space center. The decoherence effect on PASTS is examined by the analytical expression of WF. It is found that a longer threshold value of decay time is included in single PASTS than in single-photon subtraction STS.