Photonic Integration of Site-Controlled van der Waals Emitters for On-Demand Entangled-Photon Pair Generation

近50年来，科学家们一直在探索量子光产生的方法，从分离单个原子一次发射单个光子开始。量子光是基础科学研究和新兴量子技术的重要资源，包括安全通信、信息处理和精密计量。现在，通过在材料结构中引入单个缺陷，可以在固态原子薄材料（称为二维材料）中创建单个原子状发射器。通过用激光脉冲照射缺陷，单光子一次一次地按需从缺陷中发射出来。该项目旨在证明，也有可能精确地设计材料缺陷特性，以产生纠缠的按需光子对。该研究还将材料与芯片级硅光子器件集成，将光限制在极小的体积内，以提高光发射效率。最终，这项研究为如何控制原子薄材料和器件的特性提供了重要的见解，从而为量子信息中的新应用提供了有效的量子光产生。该项目为材料加工和组装、光子器件制造和量子测量方面的科学家和工程师提供了宝贵的培训机会，并通过高中生量子力学短期实践课程和向年轻学生介绍原子薄材料的暑期讲习班，为社区参与提供了机会。在硅基光子学中集成能够按需产生单光子和纠缠光子的量子光源，将使具有低尺寸、重量、功率和成本的实用和可扩展的量子技术成为可能；然而，由于硅光子学中缺乏合适的光源，需要新的器件概念。最近在原子薄范德华材料中发现的单光子发射器为解决这一需求提供了一个有希望的新方向。这些材料在集成光子学方面具有独特的优势，因为它们可以很容易地转移到各种材料平台上，并且它们具有缺陷态，可以作为单光子和相关光子的明亮源，但纠缠光子对的产生尚未得到证实。该项目的第一个目标是利用应变和粒子辐照来设计单层半导体中的位置控制单量子发射器，这些发射器能够按需产生纠缠光子对，这将用量子光学计量技术来表征。第二个目标是通过使用干转移技术与光子波导和谐振器集成来提高发射亮度和纠缠质量。这项研究将促进我们对原子薄材料中量子光产生的基本特性及其对量子技术的潜在影响的理解，填补了长期寻求的可扩展、按需量子光源与硅基光子学兼容的需求。该项目将为跨学科领域的学生研究人员提供实践培训，包括纳米技术、原子薄材料加工和表征、光子器件制造和量子光学测量。该项目还将通过为高中生开设一门新的短期课程，通过沉浸式实践活动介绍量子力学的几个关键基本概念，与社区建立紧密的联系。一个周末的暑期科学研讨会将为学生们提供学习原子薄材料如何改变技术以产生社会影响的机会。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。

Scientists have been exploring methods for quantum light generation for nearly 50 years, beginning with the isolation of a single atom emitting individual photons at a time. Quantum light is an essential resource for both fundamental scientific research and emerging quantum technologies, including secure communications, information processing, and precision metrology. It is now possible to create individual atom-like emitters in solid-state atomically thin materials, known as two-dimensional materials, by introducing individual defects in the material structure. By irradiating a defect with a laser pulse, single photons are emitted from the defect one-at-a-time and on demand. This project seeks to demonstrate that it is also possible to precisely engineer the material defect properties for the generation of on-demand photon pairs that are entangled. The research also integrates the materials with chip-scale silicon photonic devices that confine the light to extremely small volume to enhance the light emission efficiency. Ultimately, this research provides significant insight into how to control the properties of atomically thin materials and devices for efficient quantum light generation for new applications in quantum information. This project provides valuable training opportunities for scientists and engineers in materials processing and assembly, photonic device fabrication, and quantum measurements, as well as community engagement through hands-on short courses in quantum mechanics for high-school students and summer workshops introducing young students to atomically thin materials. The integration of quantum light sources capable of producing single and entangled photons on demand in silicon-based photonics would enable practical and scalable quantum technologies with low size, weight, power, and cost; however, due to the lack of suitable sources in silicon photonics, new device concepts are needed. The recent discovery of single-photon emitters in atomically thin van der Waals materials provides a promising new direction to address this need. These materials have unique advantages for integrated photonics in that they can be easily transferred to various material platforms and they host defect states that serve as bright sources of single and correlated photons, but entangled-photon pair generation has not yet been demonstrated. The first objective of this project is to utilize strain and particle irradiation to engineer site-controlled single quantum emitters in monolayer semiconductors that are capable of producing entangled-photon pairs on demand, which will be characterized with quantum optical metrology techniques. The second objective is to enhance the emission brightness and entanglement quality through integration with photonic waveguides and resonators using dry-transfer techniques. This research will advance our understanding of both the fundamental properties of quantum light generation in atomically thin materials as well as their potential impact on quantum technologies, filling a long-sought need for scalable, on-demand quantum light sources compatible with silicon-based photonics. The project will provide hands-on training for student researchers in interdisciplinary fields including nanotechnology, atomically thin materials processing and characterization, photonic device fabrication, and quantum optical measurements. The project will also establish a strong engagement with the community through a new short course for high-school students with hands-on immersive activities introducing several key fundamental concepts of quantum mechanics. A weekend summer science workshop will be offered for students to learn about how atomically thin materials are transforming technology to make a societal impact.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.