论文标题
表征和量化量子仪器的不相容性
Characterizing and quantifying the incompatibility of quantum instruments
论文作者
论文摘要
量子设备的不兼容是量子理论的基石之一，量子测量和通道的不相容性已与某些信息理论任务中的量子优势联系在一起。在这项工作中，我们专注于量子仪器不兼容的问题较低的问题，即量子仪器的不兼容，即整个描述测量过程的设备，既考虑了经典的测量结果和量子验证后的测量状态。特别是，我们专注于最近引入的工具平行兼容性的概念，该概念被认为是仪器兼容性的自然概念。我们介绍 - 与测量和通道的情况类似 - 量子仪器的不兼容鲁棒性并在其上得出了普遍的界限。然后，我们证明量子仪器的后处理是平行兼容性的免费操作。最后，我们提供了界限紧密的乐器家庭，以及兼容不可兼容的工具的家庭。
Incompatibility of quantum devices is one of the cornerstones of quantum theory, and the incompatibility of quantum measurements and channels has been linked to quantum advantage in certain information theoretic tasks. In this work, we focus on the less well-explored question of the incompatibility of quantum instruments, that is, devices that describe the measurement process in its entirety, accounting for both the classical measurement outcome and the quantum post-measurement state. In particular, we focus on the recently introduced notion of parallel compatibility of instruments, which has been argued to be a natural notion of instrument compatibility. We introduce -- similarly to the case of measurements and channels -- the incompatibility robustness of quantum instruments and derive universal bounds on it. We then prove that post-processing of quantum instruments is a free operation for parallel compatibility. Last, we provide families of instruments for which our bounds are tight, and families of compatible indecomposable instruments.
