100维频率仓量子态的机会性全重构
Opportunistic full reconstruction of 100-dimensional frequency-bin quantum states
- University of California, Berkeley（加州大学伯克利分校）
- Purdue University（普渡大学）
- Università di Pavia（帕维亚大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究提出一种结合自适应测量与贝叶斯推断的阈值量子态层析方法，利用双光子频率梳的稀疏性，以仅1.9%的测量资源实现了100维频率仓纠缠态的全重构，比此前记录提升56%，为高维光子量子系统表征提供了高效且无需先验假设的新工具。
AI中文摘要：
频率仓编码通过提供与电信基础设施兼容的高维量子态（qudit），为光子量子信息处理提供了可扩展的平台。然而，表征这些系统仍然具有挑战性，因为传统的量子态层析成像所需的测量资源随维度迅速增加，加之在多个频率模式上同时实现可控测量的困难。在此，我们解决了这些挑战，并利用自适应测量演示了纠缠频率仓量子态的阈值量子态层析成像，该测量利用了高度纠缠的双光子频率梳的稀疏性。结合贝叶斯推断，我们实验演示了希尔伯特空间维度高达$d^2=100$的双光子频率梳的全态估计——比之前的记录提高了56%——而仅执行了传统层析完整方法所需测量的1.9%。这项工作证实了测量感知方法在表征高维光子量子系统方面的前景，为全层析成像解锁了新的工具，这些工具硬件高效、状态感知，且无需对状态结构进行先验假设。
英文摘要：
Frequency-bin encoding provides a scalable platform for photonic quantum information processing by enabling high-dimensional qudit states compatible with the telecommunications infrastructure. However, characterizing these systems remains challenging, as conventional quantum state tomography requires measurement resources that increase rapidly with dimensionality, compounded by the difficulty of implementing controllable measurements across many frequency modes at once. Here, we address these challenges and demonstrate threshold quantum state tomography of entangled frequency-bin qudits using adaptive measurements that exploit the sparsity of highly entangled biphoton frequency combs. Combined with Bayesian inference, we experimentally demonstrate full state estimation of biphoton frequency combs with Hilbert space dimensions up to $d^2=100$---a 56% increase over the previous record---all while performing a mere 1.9% of the measurements required by conventional tomographically complete approaches. This work confirms the promise of measurement-aware approaches for characterizing high-dimensional photonic quantum systems, unlocking new tools for full tomography that are hardware-efficient, state-aware, and free from a priori assumptions about state structure.
