标题： 高斯瑞尼-2关联在非简并三能级激光器中 显示英文标题

标题： Gaussian Rényi-2 correlations in a nondegenerate three-level laser

摘要： 量子关联是各种量子信息处理任务中的关键组成部分。退相干过程对实现这些量子任务施加了限制。因此，了解耗散噪声系统中量子关联的行为具有重要意义。在这里，基于高斯Rényi-2熵，我们分析了双模高斯态$\rho_{AB}$中的纠缠和量子失谐。模式$A$($B$) 在非简并三级级联激光器的第一个(第二个)跃迁中生成。使用实际的实验参数，我们表明通过引入更多的量子相干性，可以产生并增强纠缠和失谐。在热噪声下，纠缠被发现更脆弱，有迅速消失的趋势。而量子失谐表现出冻结行为，在较宽的温度范围内可以被捕获。令人惊讶的是，我们发现纠缠可以超过量子失谐，这与基于前者只是后者的一部分这一假设所预期的结果相反。最后，我们通过数值和分析方法表明，通过对模式$B$进行高斯测量可以捕获最佳量子失谐。获得的结果表明，非简并三级激光器可能是一些量子信息任务的宝贵资源，特别是对于那些不需要纠缠的任务。 显示英文摘要

摘要： Quantum correlation is a key component in various quantum information processing tasks. Decoherence process imposes limitations on achieving these quantum tasks. Therefore, understanding the behavior of quantum correlations in dissipative-noisy systems is of paramount importance. Here, on the basis of the Gaussian R\'{e}nyi-2 entropy, we analyze entanglement and quantum discord in a two-mode Gaussian state $\rho_{AB}$. The mode $A$($B$) is generated within the first(second) transition of a nondegenerate three-level cascade laser. Using realistic experimental parameters, we show that both entanglement and discord could be generated and enhanced by inducing more quantum coherence. Under thermal noise, entanglement is found more fragile having a tendency to disappear rapidly. While, quantum discord exhibits a freezing behavior, where it can be captured within a wide range of temperature. Surprisingly, we find that entanglement can exceed quantum discord in contrary to the expectation based on the assumption that the former is only a part of the later. Finally, we show numerically as well as analytically that optimal quantum discord can be captured by performing Gaussian measurements on mode $B$. The obtained results suggest that nondegenerate three-level lasers may be a valuable resource for some quantum information tasks, especially, for those do not require entanglement.