100公里上具备可组合安全性的全集成连续变量量子密钥分发
Fully integrated continuous-variable quantum key distribution with composable security over 100 km
- Shanghai Jiao Tong University（上海交通大学）
- Donghua University（东华大学）
- Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）
- Hefei National Laboratory（合肥国家实验室）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究开发了一种全集成连续变量量子密钥分发平台，采用混合集成激光器等器件，通过贝叶斯算法实现稳健相位锁定，在100公里处获29.3 kbps可组合有限尺寸密钥率，推进了芯片基量子网络发展。
AI中文摘要：
量子密钥分发（QKD）通过物理定律保障信息论安全，但其大规模部署需要紧凑、可量产的光子终端。连续变量量子密钥分发（CV-QKD）凭借与电信兼容、室温相干检测的特性，非常适合这一转型。然而，在长距离QKD中，将全片上核心终端集成、室温运行、高损耗容忍度以及可组合端到端安全性统一起来，仍是一个关键瓶颈。在此，我们报告了一种全集成CV-QKD平台，其中两个混合III-V/硅氮化物（Si₃N₄）集成激光器、一个硅发送器和一个硅相干接收器实现了核心终端功能，在25至150公里的光纤链路上采用本振（LLO）运行。一种贝叶斯机器学习算法在可组合安全性所需的长记录中维持稳健的相位锁定，始终优于传统的无迹卡尔曼滤波器，而速率匹配的多维协调方法接近香农极限。该系统在100公里处，基于1400亿个符号的块，认证出可组合有限尺寸密钥率为29.3 kbps；在有限尺寸分析下125公里处为12.9 kbps，在渐近分析下150公里处为9.17 kbps。通过实现集成CV-QKD中报告的最长有限尺寸和渐近传输距离以及最高的每符号密钥率，这项工作推进了实用化芯片基量子网络的发展。
英文摘要：
Quantum key distribution (QKD) guarantees information-theoretic security by the laws of physics, but deployment at scale requires compact, manufacturable photonic terminals. Continuous-variable QKD (CV-QKD) is well suited for this transition through telecom-compatible, room-temperature coherent detection. However, unifying full on-chip core terminal integration, room-temperature operation, high loss tolerance, and composable end-to-end security in long-distance QKD remains a key bottleneck. Here we report a fully integrated CV-QKD platform in which two hybrid III--V/Si$_3$N$_4$ integrated lasers, a silicon transmitter, and a silicon coherent receiver implement the core terminal functions, operating with a local local oscillator (LLO) over fibre links of 25--150 km. A Bayesian machine-learning algorithm maintains robust phase lock throughout the long records required for composable security, consistently outperforming the conventional unscented Kalman filter, while rate-matched multidimensional reconciliation approaches the Shannon limit. The system certifies a composable finite-size secret-key rate of 29.3 kbps at 100 km from a 140-billion-symbol block, with 12.9 kbps at 125 km under finite-size analysis and 9.17 kbps at 150 km under asymptotic analysis. By establishing the longest finite-size and asymptotic reaches and the highest secret-key rate per symbol reported for integrated CV-QKD, this work advances the development of practical chip-based quantum networks.
