Quantum Communication Circuits on a CMOS Chip (QC4)

物联网的出现越来越多地涉及到金融交易、医疗档案、涉及国家安全的数据等机密和秘密数据的传输。这些应用增加了未来数据网络对隐私和身份验证的需求。传统加密工具的安全性依赖于数学过程（如分解大数）的计算难解性，因此原则上是脆弱的。这种脆弱性在过去几十年探索的量子光学技术中是不存在的。然而，在目前的方法中，量子网络利用了不同节点之间最明显的独立量子点对点传输链路，这使得扩展量子网络变得越来越复杂。此外，量子网络技术使用基于自由空间光学和/或将自由空间与光纤相结合的混合系统的实现。然而，这些方法无法扩展；它们体积庞大，无法处理具有大量节点的网络中的高度复杂性。该项目的愿景是在硅光子芯片上开发量子通信电路，以满足未来量子网络的社会需求，利用多纠缠和单光子携带量子比特。具体而言，本方案着重于基于CMOS技术制造的量子材料源、器件和电路的实验实现和理论分析，用于可扩展的量子秘密共享网络。提出的利用多能量纠缠和单量子比特携带光子的研究将使下一代量子网络的构建成为可能，对网络安全产生前所未有的影响。该项目将为研究生和本科生提供量子光学方面的科学培训，并作为推广、教育和与初中和高中合作的平台。为满足下一代量子网络对网络安全的需求，本项目重点在氮化硅材料平台上，利用能够通过下转换非线性过程产生时间bin纠缠三重态的节点，实验实现和分析量子秘密共享网络。生成的多光子用于制备高保真的预示单光子，格林伯格-霍恩-塞林格（GHZ）时间bin纠缠态和远程纠缠态，以支持真正的网络拓扑，而不是通常使用的支持点对点链路的双光子纠缠态。为了构建这样的网络，我们将利用制造代工厂开发利用CMOS工艺的芯片上的新型量子光学器件和组件。因此，本课题的目标是在CMOS兼容芯片上对量子秘密共享网络的量子通信器件、元件和电路进行全面的构建和实验验证。具体目标包括分析，设计，制造，测试和演示(i)生成三重态时间bin纠缠光子以创建高保真的预告单光子，（ii）准备GHZ态，（iii）准备芯片上的远程纠缠态，（iii）演示芯片上的量子探测电路，以及（iv）演示芯片上的量子中继电路。拟议的研究在本质上是变革性的，因为它不仅标志着在芯片上集成廉价和紧凑的量子通信电路的第一步，而且还为支持未来社会网络安全需求的量子通信网络系统的实际实现提供了一条途径。该项目将为研究生和本科生提供量子光学和量子通信方面的科学培训，并作为拓展、教育和与初中和高中合作努力的基础。不同种族、性别和经济背景的学生参与科学、技术、工程和数学（STEM）将通过正在进行的RET、REU和COSMOS活动继续进行。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。

The emergence of Internet of Things increasingly involves transmission of confidential and secret data such as financial transactions, medical files, and data related to national security. These applications have increased the need for privacy and authentication in future data networks. Traditional encryption tools rely for their security on computational intractability of mathematical procedures such as factoring large numbers, and are therefore, in principle vulnerable. This vulnerability is absent in quantum optics technologies that have been explored during the past few decades. However, in current approaches, quantum networks exploit the most obvious independent quantum point-to-point transmission links between different nodes, making scaling up quantum networks increasingly complicated. Moreover, the technology for quantum networks uses realizations based on free space optics and/or hybrid systems combining free space with fiber optics. These approaches, however, do not scale; they are bulky, and cannot handle the high level of complexity in a network with a large number of nodes. The vision of this project is to develop quantum communication circuits on a silicon photonic chip to meet the societal needs of future quantum networks, exploiting multiple entangled and single-photons carrying qubits. Specifically, this proposal is focused on the experimental realization and theoretical analysis of quantum material sources, devices and circuits manufactured with CMOS technology for scalable quantum secret sharing network. The proposed research on exploiting multiple energy-entangled and single qubit carrying photons will enable the construction of next generation quantum networks with unprecedented impact on cybersecurity. The project will provide scientific training in quantum optics for students at graduate and undergraduate levels as well as serve as a platform for outreach, education and collaborative efforts with middle and high schools. Technical description To meet the needs of next generation quantum networks for cybersecurity, this project is focused on experimental realization and analysis of a quantum secret sharing network utilizing nodes capable of generating time-bin entangled triplets via a down-conversion nonlinear process in the silicon nitride material platform. The generated multiple photons are used to prepare high-fidelity heralded single photons, Greenberger-Horne-Zeilinger (GHZ) time-bin entangled states and remote entanglement states in support of a true network topology in contrast to commonly used two-photon entanglement supporting point-to-point links. To construct such a network we will develop novel quantum optical devices and components on a chip exploiting CMOS processes with use of fabrication foundries. Therefore, the goal of this proposal is to carry out a comprehensive approach in construction and experimental validation of quantum communication devices, components and circuits on a CMOS compatible chip for quantum secret sharing network. The specific objectives include analysis, design, fabrication, testing and demonstration of (i) generation of triplet time-bin entangled photons to create high fidelity heralded single photons, (ii) preparation of GHZ states, (iii) preparation of remote entanglement states on a chip, (iii) demonstration of quantum detection circuit on a chip, and (iv) demonstration of quantum relay circuit on a chip. The proposed research is transformative in nature as it will not only mark the first step toward integration of inexpensive and compact quantum communication circuits on a chip, but also offer a route to practical realization of quantum communication network systems in support of future societal need in cybersecurity. The project will provide scientific training in quantum optics and quantum communications for students at graduate and undergraduate levels as well as serve as a basis for outreach, education and collaborative efforts with middle and high schools. Engagement of students of diverse ethnicity, gender and economic backgrounds in Science, Technology, Engineering and Mathematics (STEM) will be continued via the ongoing RET, REU, and COSMOS activities.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.