RAISE-EQuIP: Quantum repeater for long-distance quantum communication enabled by non-Gaussian cluster states on a scalable hybrid aluminum nitride and silicon nanophotonic platform

saikat Guha, Linran Fan, Dan Kilper，亚利桑那大学量子物理学原理将实现更优越的计算能力、更好的传感器和安全的通信，这些通信被证明是任何对手都无法破坏的。大多数这些进步将由一种称为量子纠缠的新信息资源实现。量子中继器是实现量子网络信息基础设施的最重要组成部分之一，它能够在长距离上以高速率产生和分配纠缠，量子中继器是一种量子处理器，它将位于未来量子互联网的节点上，增强当前的网络路由器。我们的项目吗?S的目标是研究、开发和测试量子中继器的设计，该设计将在集成光子平台中紧凑地实现，该平台可根据需要产生复杂的多光子纠缠态。该项目的成功完成将使共享纠缠的各种应用成为可能，包括面向未来的安全通信和多方安全计算，用于远超成像和遥感的纠缠辅助分布式传感器，并将通过让我们实验比迄今为止创造的任何纠缠状态，在化学和高能物理等领域实现新的科学发现。尽管我们的主要目标是研究量子中继器的可扩展片上设计，但理论工作将帮助我们深入了解如何构建使用光子编码量子比特的通用和专用量子处理器，而我们将设计的多功能纳米光子平台将对各种量子支持的光子信息处理具有价值，并应用于分布式传感和分布式云量子计算。由于量子信息科学的高度跨学科性质，特别是我们的项目团队，我们的教育和推广计划将在培养物理、光学科学、电气和材料科学与工程、计算机网络理论和数学交叉领域的多样化和强大的劳动力方面产生特别广泛的影响。构建量子中继器的最大挑战是缺乏高质量的量子存储器、高速率高保真的物质-光子纠缠源和高效的量子态保持频率转换，以使电信波长量子光子与量子存储和处理单元兼容。我们的项目吗?S的目标是研究和开发一种量子中继器的设计，该中继器不需要量子存储器或量子互转换，而是使用本地生成的许多光子模式的复杂纠缠态的集成光子源，通过对光子丢失进行量子纠错提供逻辑量子比特（量子位）的虚拟存储来取代量子存储器的作用。这种中继器，被称为全光子中继器，已经被我们团队的成员提出和最近的研究。但现有的中继器工作需要数百万个近乎完美的单光子源和探测器，以及在每个中继器节点上提供极低损耗的线性光波导。我们的关键见解是开发一种替代方案，该方案利用最近证明的数千种模式的光子多模压缩纠缠态作为群集源，但紧凑地构建在氮化铝-硅混合光子平台上。并在这些模式的一个子集上使用光子数检测，将其转换为具有通用量子能力的编码簇态，并在所谓的类似薛定谔猫的量子比特基础上，开发一种新的逻辑量子比特编码到“非高斯”簇态。这个项目的目标是：(1)建立了技术上可行的基于连续变量（CV）纠缠簇源的全光子量子中继器的理论设计原则；(2)开发了一个紧凑、通用的集成纳米光子平台，用于生成和操纵CV簇态；(3)实现了非高斯通用簇的高速率直接按需生成；(4)第一次测量在一个量子中继链路上的纠缠分布，该链路超过了纠缠产生的基本直接传输速率上限。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。

RAISE-EQuIP: Quantum repeater for long-distance quantum communication enabled by non-Gaussian cluster states on a scalable hybrid aluminum nitride and silicon nanophotonic platformSaikat Guha, Linran Fan, Dan Kilper, University of ArizonaPrinciples from quantum physics will enable far superior computational capabilities, better sensors and secure communications that are provably unbreakable by any adversary. Most of these advancements will be enabled by a new information resource called quantum entanglement. One of the most important building blocks to realize a quantum-enabled network information infrastructure that is capable of generating and distributing entanglement at high rates over long distances is the quantum repeater a quantum enabled processor that will sit at the node of the future quantum internet, augmenting the current-day network router. Our project?s goal is to research, develop and test a design for the quantum repeater, which will be realized compactly in an integrated photonic platform that produces complex many-photon entangled states on demand. The successful completion of this project will enable various applications of shared entanglement, including future-proof secure communications and multi-party secure computations, entanglement-assisted distributed sensors for far superior imaging and remote sensing, and will enable new science discoveries in areas such as chemistry and high-energy physics by letting us experiment with entangled states larger than any created so far. Even though our main thrust is to research a scalable on-chip design of a quantum repeater, the theoretical work will help us develop a deep understanding of building general and special-purpose quantum processors that use photons to encode the qubit, whereas the versatile nanophotonic platform we will design will be of value to various quantum enabled photonic information processing with applications to distributed sensing and distributed cloud-based quantum computing. Because of the highly-interdisciplinary nature of quantum information science, and our project team in particular, our education and outreach program will have a particularly broad impact in training a diverse and strong workforce at the intersection of physics, optical sciences, electrical and material science and engineering, computer network theory, and mathematics. The biggest challenge in building a quantum repeater has been the lack of good-quality quantum memories, high-rate good-fidelity matter-photon entanglement sources, and high-efficiency quantum-state-preserving frequency interconversion so as to make a telecom-wavelength quantum photon be compatible with the quantum storage and processing units. Our project?s goal is to research and develop a design of a quantum repeater that does not need quantum memories or quantum interconversion, but uses an integrated photonic source of locally-generated complex entangled states of many photonic modes to replace the action of the quantum memory by providing virtual storage of a logical quantum bit (qubit) using quantum error correction against photon loss. Such repeaters, known as all-photonic repeaters, have been proposed and recently researched by members of our team. But existing work on such repeaters need millions of near-perfect single-photon sources and detectors, along with extremely low-loss linear-optical waveguides be supplied at each repeater node. Our key insight is to develop an alternative scheme that leverages recently-demonstrated photonic multi-mode-squeezed entangled states of thousands of modes as the cluster source, but built compactly on a hybrid Aluminum Nitride - Silicon photonic platform, and use photon number detection on a subset of those modes to cast that into a universal-quantum-capable coded cluster state and develop a new logical qubit encoding into that "non-Gaussian" cluster state in a so-called Schrodinger-cat-like qubit basis. The goals of this project are: (1) establishing the theoretical design principles of a technologically-feasible all-photonic quantum repeater based on a continuous-variable (CV) entangled cluster source, (2) developing a compact, versatile integrated nanophotonic platform for generating and manipulating CV cluster states, (3) realizing direct on-demand generation of non-Gaussian universal clusters at high rates, and (4) the first measurement of entanglement distribution over one quantum repeater link that exceeds the fundamental direct-transmission rate upper limit for entanglement generation.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.