Nonclassical properties of Hermite polynomial's excitation on squeezed vacuum and its decoherence in phase-sensitive reservoirs

We introduce Hermite polynomial excitation squeezed vacuum (SV) and then investigate analytically the nonclassical properties according to Mandel's Q parameter, second correlation function, squeezing effect and the negativity of the Wigner function (WF). It is found that all these nonclassicalities can be enhanced by Hermite polynomial operation and adjustable parameters (mu and nu). In particular, the optimal negative volume (NV) of WF can be achieved by modulating mu and nu for higher excitation. The decoherence effect of phase-sensitive environment on this state is examined. It is shown that the NV with higher order diminishes more quickly than that with a lower one, which indicates that single-photon subtraction SV presents more robustness. The parameter of reservoirs can be effectively used to improve the nonclassicality.