AI 中文总结
研究连续变量量子密钥分发中理论与实际调制的差距，提出基于海森堡不确定性原理的安全框架，引入多模纠缠源模型，建立星座与密钥率映射，实现高阶星座安全分析并经实验验证，还为探索非高斯系统特性提供范例。
AI 中文摘要
连续变量量子密钥分发因其能与现有光通信基础设施无缝集成，成为可扩展量子网络的一个引人注目的框架。然而，理论上需要理想高斯调制的协议与实际高速硬件所要求的受限离散调制信号之间仍存在根本差距。当前离散调制的安全证明依赖半定规划，对于高阶星座存在计算开销过大的问题，且缺乏对非高斯性的直接物理洞察。在本文中，我们通过开发一个安全框架克服了这一限制，该框架摒弃半定规划，转而采用基于海森堡不确定性原理的方法。通过引入多模纠缠源模型来表征非高斯态制备，我们建立了星座几何与密钥率之间的明确映射。此框架有效量化了硬件受限、有限态制备的安全影响，实现了高阶星座下的数值和解析安全分析。我们在离散组件和集成光子平台上对方法进行了实验验证，表明具有256个星座点的正交幅度调制格式可渐近接近高斯容量极限。除量子密钥分发外，通过源模式扩展收紧不确定性约束边界的原理为探索复杂非高斯系统的信息理论特性提供了一个范例。
英文摘要
Continuous-variable quantum key distribution is a compelling framework for scalable quantum networks due to its seamless integration with existing optical communication infrastructure. However, a fundamental gap persists between theoretical protocols requiring ideal Gaussian modulation and the constrained, discrete-modulated signals dictated by practical high-speed hardware. Current security proofs for discrete modulation rely on semidefinite programming, which suffers from prohibitive computational overhead for high-order constellations and lacks direct physical insight into non-Gaussian modulation.In this Letter, we overcome this limitation by developing a security framework that obviates semidefinite programming in favor of an approach grounded fundamentally in the Heisenberg uncertainty principle. By introducing a multi-mode entanglement-source model to characterize non-Gaussian state preparation, we establish an explicit mapping between constellation geometry and the secret key rate. This framework effectively quantifies the security implications of hardware-limited, finite state preparation, enabling both numerical and analytical security analysis under high-order constellations. We experimentally validate our method on both discrete-component and integrated photonic platforms, demonstrating that a quadrature amplitude modulation format with 256 constellation points can asymptotically approach the Gaussian capacity limit. Beyond quantum key distribution, the principle of tightening uncertainty-constrained bounds via source-mode expansion offers a paradigm for exploring the information-theoretic properties of complex non-Gaussian systems.
Comments7 pages, 5 figures
