Decoherence of Photon-Added Schrodinger Cat States in Thermal Environment

We analyze the statistical properties and decoherence of the field states produced by adding any number of photons to the Schrodinger Cat states (SCSs) in a thermal environment. It is found that the normalization factor of PA-SCS is the Hermite polynomial of the coherent factor alpha. The statistical properties and decoherence is discussed by deriving analytically the time evolution of the Q-function, Wigner function and the photon-number distribution. It is shown that the single photon-added even SCSs, the Wigner function is always positive in the whole phase space when kappa t exceeds the threshold value . This implies that the single photon-added even SCSs possesses a robustness due to the presence of photon-addition, which can also be seen from the point of view of the volume of negative region of Wigner function.