论文标题
基于连贯的证人检测和估计相干性
Detecting and estimating coherence based on coherence witnesses
论文作者
论文摘要
量子相干性具有从量子热力学到量子计量学，量子通道辨别甚至量子生物学的广泛应用。因此，检测和量化相干性是量子资源理论中的两个基本问题。在这里，我们介绍了可行的方法，通过为任何有限维状态构建连贯的证人来检测和估计连贯性。我们的连贯性目击者通过测试证人的期望值是否为负面来检测一致的国家。根据我们的证人构建方法提出和讨论了两名典型的连贯证人，它们也用于估计连贯性的鲁棒性，$ l_1 $ - norm和$ l_2 $ - 连贯措施的norm。此外，我们通过证明我们的证人比以前的证人更强大，将我们的连贯见证人之一与先前的证人进行了比较。我们还提出了连贯性在量子计量任务中的应用，在该任务中，我们通过测量我们的连贯性证人来估计一个未知参数。
Quantum coherence has wide-ranging applications from quantum thermodynamics to quantum metrology, quantum channel discrimination and even quantum biology. Thus, detecting and quantifying coherence are two fundamental problems in quantum resource theory. Here, we introduce feasible methods to detect and estimate the coherence by constructing coherence witnesses for any finite-dimensional states. Our coherence witnesses detect coherent states by testing whether the expectation value of the witness is negative or not. Two typical coherence witnesses are proposed and discussed based on our witness-constructing method, which are also used to estimate the robustness of coherence, $l_1$-norm and $l_2$-norm of coherence measures. Furthermore, we compare one of our coherence witness with a previously introduced witness, by proving that our witness is strictly stronger than that previous witness. We also present an application of coherence in a quantum metrology task, in which we estimate an unknown parameter by measuring our coherence witness.
