QuSeC-TAQS: Quantum Sensing with Strongly Nonclassical Light Based on Third-Order Nonlinearities

光量子传感有望通过利用量子相关和纠缠等资源，彻底改变对各种物理量（如分子光谱或频率）的极其敏感的检测。事实上，它已经被部署在一些小众领域，比如引力波探测器。然而，与经典传感器相比，仍有几个未解决的挑战阻碍了量子传感器的大规模应用。例如，对真空兼容性和低温操作的严格要求，加上产生脆弱量子资源的大量额外复杂性，往往限制了这些量子传感器可以广泛部署的环境。该团队的目标是克服这些限制，使用室温量子源产生所谓的压缩光，利用量子相关性将噪声降低到经典界限以下。这个多学科团队结合了应用物理学、量子科学、电子工程、生物物理学、机械工程、材料科学、纳米制造和生物工程等领域的交叉专业知识。根据该计划开发的量子光源将是片上的，紧凑的，可扩展的，并通过先进的纳米制造技术大规模生产，允许与传感器计划的无缝集成。此外，该团队将通过与联邦实验室的合作，为研究生和本科生提供多学科指导，以及设计针对新兴量子技术的量身定制的新课程，为培养量子就绪的劳动力做出贡献。该项目结合了量子光产生和探测方面的基本创新，以及设备设计方面的实际进展，以实现可扩展集成系统的改进传感性能。这项工作将开发三个量子光产生平台——都基于无处不在的三阶克尔非线性，但成熟度不同——用于量子传感应用。该项目中用于增强传感的量子资源包括称为压缩态的非经典光态，其表现出低于真空的量子噪声降低。铷蒸气、氮化硅和碳化硅这三种平台具有超低损耗、高约束或大参数增益等独特优势，但集成纳米光子平台一直受到低压缩水平的制约。为了克服这个问题，该项目的目标包括在纳米制造芯片级平台上使用四波混频在宽波长范围内产生大的压缩水平，并将其与量子传感器集成。压缩水平的提高将通过噪声抑制、器件设计、精确色散工程和多频分析方面的创新来实现。各种各样的量子传感器将受益于压缩光固有的强量子降噪及其与传感器的紧密集成。总的来说，该项目通过在相对紧凑和稳定的原子蒸气中增加便携式、频率敏捷的强非经典光源，特别是在集成纳米光子芯片级平台上，促进了量子传感的进步。该项目由量子传感器挑战项目（QuSeC-TAQS）和国际科学与工程办公室共同资助。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。

Optical quantum sensing holds promise for revolutionizing extremely sensitive detection of various physical quantities such as molecular spectra or frequencies by harnessing resources such as quantum correlations and entanglement. In fact, it is already deployed in niche areas such as gravitational wave detectors. However, several unsolved challenges remain that prevent widespread adoption of quantum sensors at scale compared to classical counterparts. For example, stringent demands on vacuum-compatibility and low-temperature operation combined with the substantial additional complexity to generate the fragile quantum resources often limit the environments in which these quantum sensors can be widely deployed. The team aims to overcome these limitations using room-temperature quantum sources generating what is called squeezed light that take advantage of quantum correlations to reduce noise below classical bounds. This multidisciplinary team combines cross-cutting expertise in applied physics, quantum science, electrical engineering, biophysics, mechanical engineering, materials science, nanofabrication and bioengineering. The quantum light sources developed under the program will be on-chip, compact, scalable, and mass-manufacturable through advanced nanofabrication techniques, allowing for the planned seamless integration with the sensors. Additionally, the team will contribute to training a quantum-ready workforce through collaborative work with federal labs, by providing multidisciplinary mentoring of graduate and undergraduate students, and by designing new tailored curricula on emerging quantum technologies.The project combines fundamental innovations in the generation and detection of quantum light with practical advances in device design towards scalable integrated systems that exhibit improved sensing performance. The effort will develop three platforms for quantum light generation – all based on the ubiquitous third-order Kerr nonlinearity, but with different levels of maturity – towards quantum sensing applications. The quantum resources harnessed in this project for enhanced sensing consist of nonclassical states of light called squeezed states, which exhibit quantum noise reduction below that of the vacuum. These three platforms of rubidium vapor, silicon nitride and silicon carbide have their unique advantages such as ultralow loss, high confinement or large parametric gain, but the integrated nanophotonic platforms have been stymied by low squeezing levels. To overcome this, the goals of the project include the generation of large squeezing levels over wide wavelength ranges using four-wave mixing on nanofabricated chip-scale platforms and their integration with the quantum sensors. The improvements in squeezing levels will be achieved through innovations in noise suppression, device design, precise dispersion engineering and multi-frequency analysis. A wide variety of quantum sensors will benefit from the strong quantum noise reduction inherent to squeezed light and their close integration with the sensor. Overall, the project promotes advances in quantum sensing by increasing access to portable, frequency-agile strongly nonclassical light sources in relatively compact and stable atomic vapors and especially in integrated nanophotonic chip-scale platforms. This project was co-funded by the Quantum Sensors Challenge for Transformative Advances in Quantum Systems (QuSeC-TAQS) program, and the Office of International Science and Engineering.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.