Integrated Photonic Chips for Generating Entangled Photon Triplets

量子信息技术是基础物理学进步的推动力，能够实现大规模安全通信、前所未有的处理器速度和更高分辨率的测量技术。这些应用需要纠缠光子的来源，这些纠缠光子作为具有有趣量子特性的信息，以及可以操纵和测量这些光子的电路。一个几乎未被探索过的方法是在一个步骤中产生纠缠光子的三联体。该方案大大简化了更大纠缠态的产生，使量子实验成为可能，填补了量子计算机发展的巨大空白。在这个项目中，研究者和他的学生将使用二氧化钛（TiO2）集成光子电路以一种强大的、可扩展的、商业上可行的格式生产三胞胎。利用他们在TiO2、非线性光学和集成光子器件方面的专业知识，该团队将开发一种直接产生电信波长纠缠三重态光子的光源。TiO2和光子集成量子电路的成熟将推动量子信息科学领域向产品商业化的方向发展。在推进上述领域的发现的同时，该项目还将通过对本科生和研究生的研究型教育，为培养未来的多学科科学家和工程师做出贡献。量子信息技术是基础理论进步的推动力，可以实现大规模安全网络、量子信息处理器以及增强的测量和光刻技术。光子学是这类技术的理想平台；然而，单光子和纠缠光子的产生、操作和探测仍然是一个挑战。虽然自发的单光子和对光子的来源很普遍，但三重光子源几乎完全没有被探索过，它们代表了量子理论基础测试和量子通信和计算预示光子对的缺失环节。此外，三重态光子源大大简化了更大纠缠态的产生。该项目将寻求开发一种可以直接产生纠缠三重态光子的源，该源可以使用三阶自发参数下转换，以4000三重态/秒的速率（比目前的实验成果大6个数量级）在电信波长（例如1500 nm）产生纠缠三重态光子。通过耦合到谐振腔，该团队将进一步提高发射率一个额外的数量级，并改善光谱控制。TiO2具有高透明度、非线性大、线性折射率高、荧光可忽略的特点，是该工艺的理想材料。该小组将利用TiO2器件中强、持续的非线性和紧密的光约束，直接在芯片上实现前所未有的三重光子产生率，在那里它们可以很容易地被路由、操纵，然后使用集成探测器进行测量。

Quantum information technologies are a driving force for the advancement of fundamental physics and enable large-scale secure communication, unprecedented processor speeds, and higher resolution measurement techniques. These applications require a source of entangled photons, which act as bits of information with interesting quantum properties, as well as circuits that can manipulate and measure these photons. An almost unexplored approach is to generate triplets of entangled photons in a single step. This scheme significantly simplifies the generation of larger entangled states, enabling exciting quantum experiments and filling a huge gap in the development of quantum computers. In this project, the investigator and his students will use titanium dioxide (TiO2) integrated photonic circuits to produce triplets in a robust, scalable, and commercially viable format. Leveraging their expertise in TiO2, nonlinear optics and integrated photonic devices, the group will develop a source that directly produces entangled triplet photons at telecommunications wavelengths. Maturation of TiO2 and photonic integrated quantum circuits will move the field of quantum information science in the direction of commercializable products. While advancing the discoveries in the fields described above, this project will also contribute to the training of future multidisciplinary scientists and engineers through research-based education of undergraduate and graduate students. Quantum information technologies are a driving force for the advancement of fundamental theories and can enable large-scale secure networks, quantum information processors, and enhanced measurement and lithographic techniques. Photonics is an ideal platform for such technologies; however, the generation, manipulation, and detection of single and entangled photons remain a challenge. While sources of spontaneous single and pairs of photons are widespread, triplet-photon sources are almost completely unexplored and represent the missing link for fundamental tests in quantum theory and heralded photon pairs for quantum communication and computation. Furthermore, a triplet-photon source significantly simplifies the generation of larger entangled states. This project will seek to developm a source that can directly produce entangled triplet photons at telecommunications wavelengths (e.g., 1500 nm) at a rate of 4,000 triplets/sec (six orders of magnitude greater than current experimental efforts) using third-order spontaneous parametric down-conversion. By coupling to a resonant cavity, the group will further enhance the emission rate by an additional order of magnitude and improve spectral control. TiO2 is the ideal material for this process because of its high transparency, large nonlinearity, high linear refractive indices, and negligible fluorescence. The group will exploit the strong, sustained nonlinearity and tight light-confinement in TiO2 devices to achieve unprecedented triplet-photon generation rates directly on chip, where they can readily be routed, manipulated, and then measured using integrated detectors.