标题： 在一般相干攻击下忠实且安全的分布式量子传感 显示英文标题

标题： Faithful and secure distributed quantum sensing under general-coherent attacks

摘要： 量子计量学和密码学可以在分布式和/或远程传感设置中结合使用，在这种设置中，具有有限量子能力的远端用户可以通过量子网络利用由量子能力强的提供者传输的量子态，以私密的方式执行量子增强的参数估计。 之前关于该主题的工作受到潜在窃听者能力的限制假设和基于中止的协议的限制，这些协议阻碍了简单的实际实现。 在这里，我们引入了单向和双向协议的理论分析和实验演示，这些协议用于分布式传感，结合了几个独特且理想的特性：(i) 安全阈值机制允许协议在低噪声情况下继续进行，并量化相对于理想估计程序的潜在篡改，从而有效铺平了广泛实际应用的道路；(ii) 基于纠缠和基于互无偏基的公式之间的等价性；(iii) 通过LOCC-de-Finetti定理对集体攻击的鲁棒性，据我们所知，这是首次。 最后，我们在基于光子的实现中展示了我们的协议，观察到保证安全阈值的可能性可能会在估计偏差方面付出重大代价，在实际环境中可能高估篡改的效果。 显示英文摘要

摘要： Quantum metrology and cryptography can be combined in a distributed and/or remote sensing setting, where distant end-users with limited quantum capabilities can employ quantum states, transmitted by a quantum-powerful provider via a quantum network, to perform quantum-enhanced parameter estimation in a private fashion. Previous works on the subject have been limited by restricted assumptions on the capabilities of a potential eavesdropper and the use of abort-based protocols that prevent a simple practical realization. Here we introduce, theoretically analyze, and experimentally demonstrate single- and two-way protocols for distributed sensing combining several unique and desirable features: (i) a safety-threshold mechanism that allows the protocol to proceed in low-noise cases and quantifying the potential tampering with respect to the ideal estimation procedure, effectively paving the way for wide-spread practical realizations; (ii) equivalence of entanglement-based and mutually-unbiased-bases-based formulations; (iii) robustness against collective attacks via a LOCC-de-Finetti theorem, for the first time to our knowledge. Finally, we demonstrate our protocols in a photonic-based implementation, observing that the possibility of guaranteeing a safety threshold may come at a significant price in terms of the estimation bias, potentially overestimating the effect of tampering in practical settings.