Abstract：
Entanglement distribution task encounters a problem of how the initial entangled state should be prepared in order to remain entangled the longest possible time when subjected to local noises. In the realm of continuous-variable states and local Gaussian channels it is tempting to assume that the optimal initial state with the most robust entanglement is Gaussian too; however, this is not the case. Here we prove that specific non-Gaussian two-mode states remain entangled under the effect of deterministic local attenuation or amplification (Gaussian channels with the attenuation factor/power gain κi and the noise parameter μi for modes i=1,2) whenever κ1μ22+κ2μ12<14(κ1+κ2)(1+κ1κ2), which is a strictly larger area of parameters as compared to where Gaussian entanglement is able to tolerate noise. These results shift the “Gaussian world” paradigm in quantum information science (within which solutions to optimization problems involving Gaussian channels are supposed to be attained at Gaussian states).
摘要：
纠缠分布任务遇到了一个问题，即如何准备初始纠缠状态，以便在受到局部噪声时保持尽可能长的纠缠时间。在连续变量状态和局部高斯信道领域，人们很容易假设具有最鲁棒纠缠的最佳初始状态也是高斯的；然而，事实并非如此。在这里，我们证明了特定的非高斯双模状态在确定性局部衰减或放大的作用下保持纠缠（高斯通道，衰减因子/功率增益κi和模式i=1,2的噪声参数μi），每当κ1μ22+κ2μ12<14（κ1+κ2）（1+κ1κ2），与高斯纠缠能够容忍噪声的情况相比，这是一个严格更大的参数区域。这些结果改变了量子信息科学中的“高斯世界”范式（在该范式中，应该在高斯状态下获得涉及高斯通道的优化问题的解决方案）。
