论文标题
Wigner函数对耗散的负性稳健性
Robustness of negativity of the Wigner function to dissipation
论文作者
论文摘要
由负值Wigner函数描述的非高斯量子状态对于量子物理学的基本测试和新兴量子信息技术都很重要。但是，它们很容易受到耗散的影响。众所周知，仅当设置的总量子效率$η$高于1/2时，Wigner函数可能存在负效率。在这里，我们证明这种情况不仅是必要的，而且是足够的条件：在满足这种情况的同时，消极情绪始终存在。同时，在明亮（多光子）非高斯量子状态的情况下，对$η$的负依赖性是高度非线性的。随着几个光子的损失，它通过数量级下降，阻碍了其实验检测。
Non-Gaussian quantum states, described by negative valued Wigner functions, are important both for fundamental tests of quantum physics and for emerging quantum information technologies. However, they are vulnerable to dissipation. It is known, that the Wigner functions negativity could exist only if the overall quantum efficiency $η$ of the setup is higher than 1/2. Here we prove that this condition is not only necessary but also a sufficient one: the negativity always persists while this condition is fulfilled. At the same time, in the case of bright (multi-photon) non-Gaussian quantum states, the negativity dependence on $η$ is highly non-linear. With the loss of several photons, it drops by orders of magnitude, hampering its experimental detection.
