光学干涉测量中利用多光子态的分布式相位传感
Distributed Phase Sensing with Multiphoton States in Optical Interferometry
AI总结：
该研究提出利用线性光学网络产生的数路径纠缠多光子态与光子数分辨探测的分布式相位传感方案，平衡光子分布可最大化相位灵敏度，且能缓解光子损耗，为量子增强分布式多模计量提供可扩展框架。
AI中文摘要：
我们研究利用可分光子输入的干涉相位估计，该输入通过线性光学网络演变为数路径纠缠态，随后经光子数分辨探测。针对分布在2N个光学模式（划分为相位编码块与参考块）的任意N光子态，推导了零相位下经典费舍尔信息的简洁解析表达式。在这些块间的所有可能光子分布中，平衡配置对每个光子数N均使相位灵敏度最大化，且呈现出唯一的相位无关响应；随着光子分布不对称性增大，可实现的灵敏度单调下降。我们进一步研究了存在实际光子损耗时该协议的鲁棒性，并将分析扩展至多接收端的分布式架构。在低光子通量区域，真空涨落从根本上限制了本地正交测量，而非局域光子数分辨测量则利用多光子干涉缓解损耗诱导的灵敏度下降。这些结果共同构建了量子增强分布式多模计量的可扩展框架。
英文摘要：
We investigate interferometric phase-estimation using separable photon inputs that evolve into number-path entangled states through linear optical networks, followed by photon-number-resolving detection. A simple analytical expression for the classical Fisher information at zero phase is derived for arbitrary $N$-photon states distributed across 2$N$ optical modes, partitioned into phase-encoding and reference blocks. Among all possible photon distributions between these blocks, the balanced configuration maximizes the phase sensitivity for every photon number $N$ and uniquely exhibits a phase-independent response. The achievable sensitivity degrades monotonically with increasing asymmetry in the photon distribution. We further investigate the robustness of the protocol in the presence of realistic photon loss and extend the analysis to distributed architectures with multiple receivers. In the low photon-flux regime, vacuum fluctuations fundamentally limit local quadrature measurements, whereas nonlocal photon-number-resolving measurements exploit multiphoton interference to mitigate loss-induced sensitivity degradation. Together, these results establish a scalable framework for quantum-enhanced distributed multimode metrology.
