NONCLASSICALITY AND DECOHERENCE OF PHOTON-ADDED THERMAL STATE
Using the normally ordered form of thermal state characteristic of average photon number n(c), we introduce the photon-added thermal state (PATS) and investigate its statistical properties, such as Mandel's Q-parameter, photon number distribution (PND), and Wigner function (WF). We then study its decoherence in a thermal environment with average thermal photon number (n) over bar and dissipative coefficient kappa by deriving analytical expressions of the WF. The nonclassicality is discussed in terms of the negativity of the WF. It is found that the WF is always positive when kappa t >= kappa t(c) = (1/2) ln (2 (n) over bar + 2)/(2 (n) over bar + 1) for any number PATS. The expression for time evolution of the PND and the tomogram of PATS are also derived analytically, which are related to hypergeometric function and single variable Hermite polynomials.
nonclassicality decoherence photon-added thermal state