双模激发压缩真空态的维格纳函数

Wigner Functions of Two-Mode Excited Squeezed Vauccm States

利用纠缠态表象下的维格纳(Wigner)算符,构造了双模激发压缩真空态的维格纳函数,并根据该函数在相空间ρ-γ中随参量m,n和r的变化关系,讨论了双模激发压缩真空态的量子干涉特性和压缩效应。结果表明,对于参量m,n不同的取值,双模激发压缩真空态的量子干涉效应的强弱不同;而对于不同的压缩参量r,双模激发压缩真空态呈现出不同程度的压缩效应。最后,根据双模激发压缩真空态的维格纳函数的边缘分布,阐明了此维格纳函数的物理意义。

Using the Wigner operator in the entangled-state representation we construct the Wigner functions of the two-mode excited squeezed vacuum states （TESVS）. In term of the variations of the Wigner functions with respect to the parameters m, n and r in the ρ-γ phase space, the quantum interference properties and squeezing effects of the TESVS are discussed. The results show that, for different values of m and n, the TESVS have different quantum interference effects, however for different squeezing parameters r the TESVS exhibit different squeezing effects. Furthermore, the physical meaning of the Wigner functions is identified according to the marginal distributions of the Wigner functions for the TESVS.