Entanglement-Assisted Communication Surpassing the Ultimate Classical Capacity
Entanglement-Assisted Communication Surpassing the Ultimate Classical Capacity
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DOI：
10.1103/physrevlett.126.250501
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发表时间：
2021-06-22
影响因子：
8.6
通讯作者：
Zhang, Zheshen
中科院分区：
文献类型：
--
作者：
Hao, Shuhong;Shi, Haowei;Zhang, Zheshen
纠缠是各种量子增强通信、传感和计算能力的基础。纠缠辅助通信（EACOMM）利用通信双方预先共享的纠缠来提高经典信息传输的速率。开创性的理论工作表明，EACOMM 可以实现远远超出光通信的极限经典容量的通信速率，但任何 EACOMM 优势的实验证明仍然难以捉摸。在这封信中，我们报告了 EACOMM 的实现超越了有损和噪声玻色通道的经典能力。我们构建了一个高效纠缠源和一个相位共轭量子接收器，以获取预共享纠缠的好处，尽管纠缠会被通道损耗和噪声破坏。我们表明，当两种协议在发射机处受到相同的功率限制时，EACOMM 的容量比传统通信的 Holevo-Schumacher-Westmoreland 容量高出 16.3%。作为实际性能基准，我们实现了具有相同编码信号特性的经典通信协议，结果表明 EACOMM 可以在相同的玻色子信道上将误码率降低高达 69%。我们的工作为在广泛的量子信息处理任务中证明量子优势开辟了一条途径。
Entanglement underpins a variety of quantum-enhanced communication, sensing, and computing capabilities. Entanglement-assisted communication (EACOMM) leverages entanglement preshared by communicating parties to boost the rate of classical information transmission. Pioneering theory works showed that EACOMM can enable a communication rate well beyond the ultimate classical capacity of optical communications, but an experimental demonstration of any EACOMM advantage remains elusive. In this Letter we report the implementation of EACOMM surpassing the classical capacity over lossy and noisy bosonic channels. We construct a high-efficiency entanglement source and a phase-conjugate quantum receiver to reap the benefit of preshared entanglement, despite entanglement being broken by channel loss and noise. We show that EACOMM beats the Holevo-Schumacher-Westmoreland capacity of classical communication by up to 16.3%, when both protocols are subject to the same power constraint at the transmitter. As a practical performance benchmark, we implement a classical communication protocol with the identical characteristics for the encoded signal, showing that EACOMM can reduce the bit-error rate by up to 69% over the same bosonic channel. Our work opens a route to provable quantum advantages in a wide range of quantum information processing tasks.