论文标题
量子通信的容量量量子中继器
Capacity-approaching quantum repeaters for quantum communications
论文作者
论文摘要
在当今的量子通信中，主要问题之一是缺乏可以同时确保高率和长距离的量子中继器设计。最近的文献已经建立了端到端的能力，这些容量是通过量子网络中量子和私人通信的最一般协议可以实现的，涵盖了量子中继器链的情况。但是，是否存在实现这种能力的物理设计仍然是一个具有挑战性的目标。在这种动机的驱动下，在这项工作中，我们为连续可变的量子中继器提供了设计，并表明它实际上可以实现这一壮举。我们还表明，即使在一个嘈杂的政权中，我们的费率也超过了Pirandola-Laurenza-Ottaviani-Banchi（PLOB）结合。我们的中继器设置是在使用无嘈杂的线性放大器，量子记忆和连续变化的铃铛测量后开发的。此外，我们提出了一个非理想模型，用于我们在设计中使用的连续变量量子记忆。然后，我们表明，如果量子链接太嘈杂和/或低质量的量子记忆和放大器，那么潜在的量子通信率将偏离理论能力。
In present-day quantum communications, one of the main problems is the lack of a quantum repeater design that can simultaneously secure high rates and long distances. Recent literature has established the end-to-end capacities that are achievable by the most general protocols for quantum and private communication within a quantum network, encompassing the case of a quantum repeater chain. However, whether or not a physical design exists to approach such capacities remains a challenging objective. Driven by this motivation, in this work, we put forward a design for continuous-variable quantum repeaters and show that it can actually achieve the feat. We also show that even in a noisy regime our rates surpass the Pirandola-Laurenza-Ottaviani-Banchi (PLOB) bound. Our repeater setup is developed upon using noiseless linear amplifiers, quantum memories, and continuous-variable Bell measurements. We, furthermore, propose a non-ideal model for continuous-variable quantum memories that we make use of in our design. We then show that potential quantum communications rates would deviate from the theoretical capacities, as one would expect, if the quantum link is too noisy and/or low-quality quantum memories and amplifiers are employed.
