RAISE-TAQS: Enhancing Classical and Quantum Information Capacities with Imperfect Resources: Experimental Implementations and Theoretical Bounds

量子信道是量子数据在不同位置之间传输的手段；它们为任何量子通信设置提供了骨干。量子通道具有许多违反直觉的性质，没有经典类比。为了解决现实信道上的量子通信问题，我们提出了一个跨学科项目，结合五位研究人员在量子资源理论、先进光子量子信息协议、光子非线性系统、光子量子态表征和精密光学测量方面的专业知识。涉及量子纠缠、非定域性和因果关系的基本问题正在被探索，同时将理论方面转化为实际的实验演示。该项目研究了现实量子和量子增强经典信息传输的问题，以及它们的增强特性如何应用于近期的计算设备，特别是与工程相关的，与实际系统中的实际收益有关。学生发展是这个项目的主要教育目标。由于这项工作在很大程度上是跨学科的，它将为来自不同专业的学生提供一个在独特环境中合作的机会。超加性/超激活和量子增强双向通信的高度非经典效应是本项目的两个主要主题。在第一种方法中，两个有噪声的量子信道在并行使用时变得更加强大，在第二种方法中，通过单个量子信道实现双向通信。这些效应的实验验证将通过包括数学和物理理论家与物理和工程实验学家一起工作的团队努力来实现。分析了低维系统中信道容量的理论限制及其行为，旨在构建适合桌面和集成光子实验部署的协议。在此基础上，利用超纠缠光子和混合纠缠光子以及腔增强非线性效应开发了新的实验技术。这些实验进展在下一代光子量子信息处理中具有强大的应用潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Quantum channels are the means by which quantum data is transmitted between different locations; they provide the backbone for any quantum communication setup. Quantum channels have many counterintuitive properties with no classical analog. To address problems in quantum communication over realistic channels, we propose an interdisciplinary project that combines the expertise of five researchers in quantum resource theory, advanced photonic quantum information protocols, photonic nonlinear systems, and photonic quantum state characterization and precision optical measurements. Fundamental questions involving quantum entanglement, nonlocality, and causality, are being explored, while translating the theoretical aspects to actual experimental demonstrations. The project investigates the problem of realistic quantum and quantum-enhanced classical information transmission and how their enhanced properties may be applied to near-term computational devices, particularly relevant for engineering, concerned with realistic gains in practical systems. Student development is a primary educational goal of this project. Since the work is largely interdisciplinary, it will provide an opportunity for students from different programs to collaborate in a unique environment. The highly non-classical effects of superadditivity/superactivation and quantum-enhanced two-way communication are two main topical focuses of this project. In the first, two noisy quantum channels become vastly more powerful for communication when used in parallel, and in the second, two-way communication is achieved through the single use of a quantum channel. Experimental validations of these effects will be attained through a team effort involving theorists in math and physics working together with experimentalists from physics and engineering. The theoretical limitations of channel capacities and their behavior in low-dimensional systems will be analyzed, aiming to construct protocols suitable for deployment in tabletop and integrated photonic experiments. Complementing this effort, new experimental techniques are developed using hyper- and hybrid-entangled photons and cavity-enhanced nonlinear effects. Such experimental advances have the potential for powerful application in next-generation photonic quantum information processing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.