Using the normally ordered Gaussian form of displaced-squeezed thermal field
characteristic of average photon number n, we introduce the photon-added
squeezed thermo state (PASTS) and investigate its statistical properties, such
as Mandel's Q-parameter, number distribution (as a Legendre polynomial), the
Wigner function. We then study its decoherence in a photon-loss channel in term
of the negativity of WF by deriving the analytical expression of WF for PASTS.
It is found that the WF with single photon-added is always partial negative for
the arbitrary values of n and the squeezing parameter r.Comment: 13 pages, 7 figure
