Statistical properties of photon-subtracted squeezed vacuum in thermal environment

摘要

We investigate statistical properties of photon-subtracted squeezed vacuum (PSSV) in a thermal environment with average thermal photon number (n) over bar and dissipative coefficient kappa by deriving the analytical expressions of the density operator and the Wigner function (WF). The normalization of m-PSSV is proved to be the m-order Lagendre polynomials. nine evolution of the photocount distribution is also related to Lagendre polynomials. The tomogram of PSSV is calculated by using the intermediate coordinate-momentum representation. Especially, the nonclassicality is discussed by virtue of the negativity of WF. It is found that the WF is always negative for all squeezing parameters lambda if kappa t<1/2 ln(2<(n)over bar>+2)/(2 (n) over bar +1) for the single-PSSV. (C) 2008 Optical Society of America