Tools for bringing Quantum Communication to Optical Networks

量子通信使用量子力学来解决通信任务。这些任务中有一些是经典交流无法完成的。最突出的例子是量子密钥分发(QKD)，它在遥远的位置创建秘密密钥，从而允许可证明的秘密通信。其他任务可以通过量子方式更有效地解决。文献中有一些有趣的应用，可以在理想的量子通信网络上运行。然而，在短期和中期内，我们还不知道如何在有限的量子通信网络上运行大多数应用程序。 光通信网络例如通过使用激光脉冲容易地支持量子力学特征。然而，抽象协议是使用理想化的量子网络来制定的，该网络发送经典比特的概括，即量子比特，而实际的光通信网络使用激光脉冲，这形成了一组受限的量子信号。我们将扩大可以在量子光通信网络上运行的应用范围。 我们将揭示在这种适应光网络的过程中出现的基本问题。这涉及到一方面确定哪些量子力学效应是抽象协议中量子优势的核心，另一方面分析这种效应是否可以使用在实际光网络实现中可访问的量子力学信号结构来利用。了解双方，然后我们将开发通用工具来匹配它们。这种定制和优化的量子协议到可用的物理系统的映射加速了它们实际实施的可能性，并使可用资源能够更有效地使用。同样的方法导致了点对点量子密钥分配的高速实现，成功地放弃了直接模仿抽象量子比特协议的追求。了解抽象量子比特通信协议适用于光网络的充要条件是评估其最终商业可行性的重要一步。

Quantum Communication uses quantum mechanics to solve communication tasks. Some of these tasks cannot be achieved by classical communication. The prominent example for this is Quantum Key Distribution (QKD) which creates secret key at distant locations, thus allowing provable secret communication. Other tasks can be solved more efficiently the quantum way. There are interesting applications in the literature that could run on an ideal quantum communication network. However, it is not known how to run most of the applications on the limited quantum-enabled communication networks that are available to us in the short and medium term. Optical Communication networks readily support quantum mechanical features, for example by using laser pulses. However, abstract protocols are formulated using an idealized quantum network that sends the generalization of classical bits, the qubits, while the practical optical communication networks use laser pulses, which form a restricted set of quantum signals. We will enlarge the range of applications that can be run on a quantum-enabled optical communication network. We will reveal the fundamental problems that arise in this adaptation to optical networks. This involves on one hand to identify what quantum mechanical effects are at the heart of the quantum advantage in abstract protocols, and on the other hand to analyze whether this effects can be exploited using the quantum mechanical signal structure that is accessible in practical optical network implementations. Knowing both sides, we will then develop general tools to match them. Such customized and optimized mapping of quantum protocols to available physical systems accelerates the possibility of their practical implementation, and enables more efficient use of available resources. The same approach led point-to-point QKD to high-speed implementations that successfully abandoned the quest to directly mimic the abstract qubit protocol. Understanding the necessary and sufficient conditions for adapting abstract qubit-inspired communication protocols to optical networks is an important step in assessing their eventual commercial viability.