标题： 高斯态的光子减法纯化 显示英文标题

标题： Purification of Gaussian States by Photon Subtraction

摘要： 光子减法可以增强纠缠，这对于纯态会引发约化态的纯度降低。 相反，通过分析单个光子减去前后高斯态的纯度，我们证明高斯态的纯度也可以增加不到20%。 一方面，这表明光子减法可以减少纠缠，另一方面，它表明它可以实现有限量的高斯态纯化。 通过一些示例的分析，我们展示了基于光子减法的纯化内在机制和适用范围。 在多模系统中，我们发现光子减法可以同时增加纠缠并纯化一些约化态。 因此，我们提出了通过抑制高斯噪声实现纯化作为光子减法在连续变量量子信息处理中的新应用。 显示英文摘要

摘要： Photon subtraction can enhance entanglement, which for pure states induces a decrease in the purity of reduced states. In contrast, by analyzing the purities of Gaussian states before and after subtracting a single photon, we prove that the purity of a Gaussian state can also be increased by less than 20%. On the one hand, it reveals that photon subtraction can reduce entanglement, and on the other hand, it reveals that it can achieve a limited amount of Gaussian state purification. Through the analysis of some examples, we demonstrate the inherent mechanism and applicable scope of photon-subtraction-based purification. In a multimode system, we find that photon subtraction can increase entanglement and purify some of the reduced states simultaneously. We thus present purification through the suppression of Gaussian noise as a new application for photon subtraction in continuous-variable quantum information processing.