Wigner Function of the Two-Mode Squeezing-Enhanced Vacuum State

We find the two-mode generalized squeezing operator with two parameters can be separated into the product of a ordinary squeezing operator S ₂(ξ) and a rotating operator R ₂(θ). Acting it on the two-mode vacuum state, one can get two-mode squeezing-enhanced vacuum state (TSEVS). Compared with the usual two-mode squeezed vacuum state, TSEVS exhibits stronger squeezing properties. With the help of the operator’s Weyl-ordering invariance under the similarity transformation, we derive the Wigner function of the TSEVS.