ExpandQISE: Track 1: Development of Er-doped Semiconductor Nanophotonics to realize Optoelectronic Capabilities for Quantum Information Applications at Telecom Wavelengths

摘要：经典信息技术使用光互连在不同的媒体平台之间传递信息。这通常是通过光纤来完成的，分别将数字1和数字0作为光开和关的脉冲进行中继。对于传统技术来说，没有必要精确控制发射或探测到多少光子，只需要能够区分明亮和黑暗。量子信息技术需要能够传输单对纠缠光子的量子互连，这更具挑战性。在这方面，一个紧凑的单光子电激活源将是一个重要的进步。一种方法是利用标准通信波长下单个铒原子发射的单光子。铒原子必须嵌入到半导体宿主中才能实现电激发，而砷化镓（GaAs）由于其成熟的生长和纳米结构是理想的。然而，仅从Er原子而不是GaAs宿主中获得发射仍然是一个挑战。提高铒原子光子发射速率的一种方法是将原子嵌入纳米腔中。该项目的主要目标是研究掺铒GaAs纳米腔器件在QISE中的应用，最终目标是开发一种在电信波长下工作的片上电抽运单光子器件。该项目汇集了来自西切斯特大学（WCU）的稀土（RE）物理学经典光电应用专家和来自特拉华大学（UD）的可扩展量子光子技术专家。此外，该合作伙伴关系还推进了一个新的3+2双学位项目，学生将在五年内获得WCU的物理学学士学位和UD的QISE硕士学位。这种加速教育轨道旨在支持低收入和代表性不足的学生，促进QISE劳动力的多样性，同时加快其发展。技术摘要：创建可扩展和可靠的QISE技术需要材料和设备平台来保持量子相干性，并提供适当的相互作用来产生和控制纠缠。宽带隙半导体中基于缺陷的量子发射器由于其可扩展性和集成潜力，已成为未来QISE应用的主要候选者。稀土掺杂绝缘体已经被广泛研究，因为嵌入的稀土离子具有尖锐、稳定的光学跃迁和长寿命，有利于高保真量子控制。然而，由于样品的可用性有限，以及与竞争的原生缺陷和背景自旋相关的挑战，稀土掺杂半导体以前并未受到QISE的类似关注。如果能够克服这些挑战，re掺杂半导体平台可以通过提供光谱稳定的电泵浦单光子源、量子存储器或在电信c波段运行的量子中继器元件来填补量子技术的重大空白。在这种方法中，单个Er离子被耦合到光子器件组件上，允许通过反聚束实验来表征掺Er的砷化镓作为单光子源。这些新器件将通过控制稀释掺杂和利用纳米光子结构提高Er离子的辐射率来实现。作为这一努力的一部分，在UD的er掺杂GaAs的生长，以及结合波导和外耦合方案的新型纳米光子器件的设计和制造，以提高光收集效率。该项目由多学科活动办公室（MPS/OMA）和技术前沿计划（TIP/TF）共同资助。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。

Non-technical Abstract: Classical information technologies use optical interconnects to relay information between different media platforms. This is typically done by fiber optics, relaying digital ones and zeros as pulses with light on and off, respectively. For classical technologies, it is not necessary to precisely control how many photons are emitted or detected, only to be able to distinguish bright from dark. Quantum information technologies require quantum interconnects that can transmit single pairs of entangled photons, which is much more challenging. In this regard, a compact electrically-activated source of single photons would be an important advance. One approach is to utilize single photons emitted from individual Erbium (Er) atoms at standard telecommunication wavelengths. The Er atoms must be embedded into a semiconductor host to enable electrical excitation, and Gallium Arsenide (GaAs) is ideal due to its well-established growth and nanofabrication. However, attaining emission only from the Er atoms, rather than the GaAs host, remains a challenge. One way to improve the rate of photon emission from Er atoms is to embed the atoms into nanocavities. The primary objective of this project is to investigate the application of Er-doped GaAs nanocavity devices for QISE, with the ultimate aim of developing an on-chip electrically-pumped single-photon device operating at telecom wavelengths. This project brings together an expert in Rare Earth (RE) physics for classical optoelectronic applications from West Chester University (WCU) and experts in scalable quantum photonic technologies from the University of Delaware (UD). Additionally, this partnership advances a new 3+2 dual degree program where students earn a bachelor's degree in physics from WCU and a master's degree in QISE from UD in five years. This accelerated educational track is designed to support low-income and underrepresented students, promoting diversity in the QISE workforce while expediting its growth.Technical Abstract: Creating scalable and reliable QISE technologies requires material and device platforms that preserve quantum coherence and provide suitable interactions to produce and control entanglement. Defect-based quantum emitters in wide bandgap semiconductors have emerged as leading candidates for future QISE applications due to their potential for scalability and integration. Rare Earth-doped insulators have been extensively studied because the embedded RE ions have sharp, stable optical transitions and long lifetimes that facilitate high-fidelity quantum control. RE-doped semiconductors, however, have not previously received similar attention for QISE due to the limited availability of samples and challenges associated with competing native defects and background spins. If these challenges can be overcome, the RE-doped semiconductor platform could fill a significant gap for quantum technologies by providing a spectrally-stable electrically-pumped single-photon source, quantum memory, or element of a quantum repeater operating in the telecom C-band. In this approach, single Er ions are coupled to photonic device components, allowing the characterization of Er-doped GaAs as a single-photon source via anti-bunching experiments. These new devices will be achieved through controlled dilute doping and by enhancing the radiative rates of the Er ions using nanophotonic structures. As part of this effort, the growth of Er-doped GaAs at UD and the design and fabrication of new nanophotonic devices incorporating waveguiding and out-coupling schemes for enhanced light-collection efficiency are established.This project is jointly funded by the Office of Multidisciplinary Activities (MPS/OMA), and the Technology Frontiers Program (TIP/TF).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.