标题： 量子网络断层扫描 显示英文标题

标题： Quantum Network Tomography

摘要： 错误是量子系统发展的根本障碍。 量子网络是由多个组件互连形成的复杂系统，会受到错误累积的影响。 表征量子网络组件引入的错误成为克服其在量子通信中耗竭效应的基本任务。 量子网络断层扫描（QNT）用于量子网络中链路错误的端到端表征。 它是一种用于构建误差感知应用、网络管理和系统验证的工具。 我们对QNT进行了概述，并介绍了其在表征量子星型网络方面的初步结果。 我们将之前定义的用于估计比特翻转信道的QNT协议应用于估计消相干信道。 我们通过评估有限样本情况下的量子Cramèr-Rao界（QCRB）和均方误差（MSE）来分析估计器的性能。 最后，我们讨论了QNT领域当前面临的挑战，并提出了未来研究的有趣方向。 显示英文摘要

摘要： Errors are the fundamental barrier to the development of quantum systems. Quantum networks are complex systems formed by the interconnection of multiple components and suffer from error accumulation. Characterizing errors introduced by quantum network components becomes a fundamental task to overcome their depleting effects in quantum communication. Quantum Network Tomography (QNT) addresses end-to-end characterization of link errors in quantum networks. It is a tool for building error-aware applications, network management, and system validation. We provide an overview of QNT and its initial results for characterizing quantum star networks. We apply a previously defined QNT protocol for estimating bit-flip channels to estimate depolarizing channels. We analyze the performance of our estimators numerically by assessing the Quantum Cram\`er-Rao Bound (QCRB) and the Mean Square Error (MSE) in the finite sample regime. Finally, we provide a discussion on current challenges in the field of QNT and elicit exciting research directions for future investigation.