标题： 基于正算子测度的相干性在标准和连贯量子态鉴别中的应用及不确定结果 显示英文标题

标题： Coherence based on positive operator-valued measures for standard and concatenated quantum state discrimination with inconclusive results

摘要： 在固定无法确定结果的输出率（FRIO）下，能够区分非正交量子态的最优测量可以分解为辅助分离输入，产生确定和无法确定的输出，然后对确定的输出进行最小错误（ME）测量（标准FRIO）或对两者都进行测量（串联FRIO）。这些测量的实现依赖于量子资源，本文研究基于正算子值测度（POVMs）的相干性作为在区分任意维度的等概率对称态时两种策略的资源。首先，我们证明在辅助分离阶段的POVM相干性分解为辅助态的相干性和系统与辅助体之间的量子失谐，这表明相干性比量子关联更基本。接下来，证明标准和串联FRIO的POVM相干性分解为状态分离和ME测量的POVM相干性度量，按每个事件发生的概率加权。由于对无法确定结果的状态进行ME区分，显示串联方案所需的相干性大于标准方案。我们通过表征三态区分中的POVM相干性，讨论了我们的结果的其他一般方面，包括输入的可区分性和无法确定结果的速率。最后，通过利用基于POVM的相干性作为密码学随机性增益的量化器，我们从生成对窃听者保密的随机位的角度讨论了标准和串联FRIO策略。 显示英文摘要

摘要： The optimal measurement that discriminates nonorthogonal quantum states with fixed rates of inconclusive outcomes (FRIO) can be decomposed into an assisted separation of the inputs, yielding conclusive and inconclusive outputs, followed by a minimum-error (ME) measurement for the conclusive ones (standard FRIO) or both ones (concatenated FRIO). The implementation of these measurements is underpinned by quantum resources, and here we investigate coherence based on positive operator-valued measures (POVMs) as a resource for both strategies in discriminating equally probable symmetric states of arbitrary dimension. First, we show that the POVM coherence in the assisted separation stage decomposes into the coherence of the ancillary state and the quantum discord between the system and the ancilla, evidencing coherence as a more elementary resource than quantum correlations. Next, it is demonstrated that the POVM coherence for standard and concatenated FRIO decomposes into the POVM coherence measures for state separation and ME measurement, weighted by the probabilities of occurrence of each event. Due to the ME discrimination of inconclusive states, the coherence required for the concatenated scheme is shown to be greater than that of the standard one. We discuss other general aspects of our results by characterizing the POVM coherence in the discrimination of qutrit states, with respect to the distinguishability of the inputs and the inconclusive rate. Finally, by exploiting POVM-based coherence as a quantifier of cryptographic randomness gain, we discuss the standard and concatenated FRIO strategies from the perspective of generating random bits that are secret to an eavesdropper.