The performance of adding or subtracting photons on two‐mode squeezed thermal states via examining the Einstein–Podolsky–Rosen (EPR) correlation, the Hillery–Zubairy (HZ) correlation, the fidelity of teleportation, and the negativity of Wigner function is theoretically investigated. The normalization factors and the teleportation fidelity are related to Jacobi polynomials, and the (evolved) Wigner functions are simply associated with two‐variable Hermite polynomials. Compared with the original squeezed thermal states, the EPR correlation and the teleportation fidelity can be enhanced by photon subtraction and basically weakened by photon addition symmetric operations, but they cannot be enhanced for both photon addition and subtraction asymmetric cases. Also, HZ correlation can provide a better option relative to the EPR correlation in detecting the entanglement, and the fidelity for teleporting a squeezed state with a large squeezing can also be enhanced via photon addition symmetric operations, in contrast to teleporting a coherent state. Additionally, the nonclassicality is discussed in terms of the negativity of the (evolved) Wigner functions, which shows that photon addition and subtraction and the squeezing cannot restrain the deteriorate of nonclassicality, and the evolved Wigner functions become Gaussian (corresponding to vacuum) with long decay times as a result of amplitude decay.

中文翻译：

---

通过添加或减去光子实现连续可变纠缠和维格纳函数负性

从理论上研究了通过研究爱因斯坦-波多尔斯基-罗森（EPR）相关性，Hillery-Zubairy（HZ）相关性，隐形传态保真度和Wigner函数的负性来研究在双模压缩热态上添加或减去光子的性能。归一化因子和隐形传真保真度与Jacobi多项式有关，而（演化的）Wigner函数仅与二变量Hermite多项式相关。与原始压缩热态相比，光子减法可以增强EPR相关性和隐形传真保真度，而光子加法对称操作则可以使EPR相关性和传声保真度基本减弱，但是光子加法和减法不对称情况都不能增强它们。也，在检测纠缠时，HZ相关性可以提供比EPR相关性更好的选择，并且与相干状态相比，通过光子加法对称操作还可以增强以较大的压缩状态传输被压缩状态的保真度。此外，根据（演化的）维格纳函数的负性讨论了非经典性，这表明光子的加减法和压缩不能抑制非经典性的恶化，并且演化后的维格纳函数长时间保持高斯分布（对应于真空）幅度衰减导致的衰减时间。