Time-Resolving Quantum Measurement Enables Energy-Efficient, Large-Alphabet Communication
Time-Resolving Quantum Measurement Enables Energy-Efficient, Large-Alphabet Communication
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DOI：
10.1103/prxquantum.1.010308
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发表时间：
2020-09-21
期刊：
影响因子：
9.7
通讯作者：
Polyakov, S., V
中科院分区：
文献类型：
--
作者：
Burenkov, I. A.;Jabir, M., V;Polyakov, S., V
信息交换需要物理状态的测量。由于量子测量的精度超出了经典的散粒噪声极限，因此它们被成功地用于开发测量工具和应用程序。特别是，量子测量增强策略用于区分非正交相干态。有效区分这些状态对于光通信网络至关重要，光通信网络现在正在接近底层物理系统的经典极限。然而，迄今为止所展示的量子增强辨别策略是基于为经典测量设计的传统通信协议，因此仅提供有限的优势。在我们的工作中，我们使用量子测量中容易获得但无法通过经典方法获得的光子检测时间。我们测量并利用这些时间来最大化我们对微弱非正交相干态的了解。我们采用旨在从这些知识中获益最多的沟通策略。我们实验中的这种整体方法在识别多个微弱非正交相干态时产生了创纪录的低错误率，这些微弱非正交相干态携带的能量相当于每比特传输信息中的一个光子。我们展示了对光学状态大字母的成功区分（4
Information exchange requires a measurement of physical states. Because quantum measurements enable accuracy beyond the classical shot-noise limit, they are successfully used to develop measurement tools and applications. In particular, quantum-measurement-enhanced strategies are used for the discrimination of nonorthogonal coherent states. The efficient discrimination of these states is crucial for optical communication networks, that are now approaching the classical limits of the underlying physical systems. However, quantum-enhanced discrimination strategies demonstrated to date are based on legacy communication protocols designed for classical measurements and thus provide only a limited advantage. In our work, we use photon detection times readily available in quantum measurement, but not accessible by classical means. We measure and use these times to maximize our knowledge about faint nonorthogonal coherent states. We employ communication strategies designed to benefit most from this knowledge. This holistic approach in our experiment has resulted in the record low error rates in discrimination of multiple faint nonorthogonal coherent states carrying energy corresponding to just one photon per bit of transmitted information. We demonstrate successful discrimination of large alphabets of optical states (4