发表机构
Indian Institute of Science, Bengaluru, India; Centre for Development of Advanced Computing (C-DAC), Chennai, India（印度科学学院; 高级计算发展中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出结合猫态编码与非局域CNOT门的受控量子通信协议，通过密度矩阵模拟证明在50公里距离上显著提升保真度，并验证了抗分束器攻击的安全性，为长距离星型量子网络上的纠错受控通信奠定理论基础。
AI 中文摘要
受控量子通信使得在发送方和接收方之间借助一个或多个控制方实现安全的状态传输成为可能。然而，在光纤网络上的实际实现受到振幅阻尼的严重阻碍，振幅阻尼会使保真度随距离呈指数下降。我们通过结合两种强大技术来解决这一挑战：用于纠错的猫态编码和用于分布式门实现的最优非局域CNOT门。该协议消除了物理位置量子比特本身需要通过光纤传输的需求，从而减少了阻尼事件。我们通过密度矩阵模拟表明，我们采用非局域CNOT操作的猫码保护协议在50公里处实现了更高的保真度，显著优于标准协议。我们分析了该协议对抗分束器攻击的安全性，并表明尽管猫码具有纠错功能，CHSH测试仍能针对分布式纠缠资源上的分束器攻击提供安全性。我们的结果表明，猫码保护的受控量子通信在当前技术下是可行的，并且在结构上可扩展到多个控制方，为研究长距离星型量子网络上纠错受控量子通信提供了理论框架。
英文摘要
Controlled quantum communication enables secure state transfer between a sender and receiver with the assistance of one or more controllers. However, practical implementation over optical fibre networks is severely hindered by amplitude damping, which reduces fidelity exponentially with distance. We address this challenge by combining two powerful techniques: cat-state encoding for error correction and optimal non-local CNOT gates for distributed gate implementation. The protocol eliminates the need for the physical position qubit itself to travel through the optical fibre, reducing damping events. We show, through density-matrix simulations, that our cat-code-protected protocol with a non-local CNOT operation achieves higher fidelity at 50 km, significantly outperforming the standard protocol. We analyse the protocol's security against beam-splitter attacks and show that CHSH tests provide security against beam-splitter attacks on the distributed entanglement resource despite the cat code's error correction. Our results establish that cat-code-protected controlled quantum communication is feasible with current technology and structurally extensible to multiple controllers, providing a theoretical framework for studying error-corrected controlled quantum communication over long-distance star quantum networks.
