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

光学量子传感通过利用量子关联和纠缠等资源，有望彻底改变对各种物理量(如分子光谱或频率)的极其灵敏的检测。事实上，它已经部署在引力波探测器等利基领域。然而，与经典传感器相比，仍有几个悬而未决的挑战阻碍了量子传感器的大规模采用。例如，对真空兼容性和低温操作的严格要求，再加上产生脆弱的量子资源的巨大额外复杂性，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，这种压缩光利用量子关联将噪音降低到经典极限以下。这个多学科团队结合了应用物理、量子科学、电气工程、生物物理学、机械工程、材料科学、纳米制造和生物工程方面的交叉专业知识。根据该计划开发的量子光源将是芯片上的、紧凑的、可扩展的，并可以通过先进的纳米制造技术进行大规模制造，从而实现与传感器的计划无缝集成。此外，该团队将通过与联邦实验室的合作，通过为研究生和本科生提供多学科指导，以及通过设计关于新兴量子技术的新的定制课程，为培训一支准备好量子的劳动力队伍做出贡献。该项目将量子光产生和检测方面的基本创新与设备设计方面的实际进步结合在一起，朝着具有更高传感性能的可扩展集成系统发展。这项努力将开发三个量子光产生平台-都基于普遍存在的三阶克尔非线性，但成熟程度不同-面向量子传感应用。在这个项目中，用于增强传感的量子资源由被称为压缩态的非经典光态组成，这种状态表现出低于真空的量子噪声降低。Rb蒸气、氮化硅和碳化硅这三个平台都有其独特的优势，如超低损耗、高限制或大的参数增益，但集成的纳米光子平台一直受到低压缩水平的阻碍。为了克服这一点，该项目的目标包括在纳米级芯片级平台上使用四波混频在宽波长范围内产生大压缩能级，并将其与量子传感器集成。压缩水平的改善将通过噪声抑制、设备设计、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大的量子噪声抑制以及它们与传感器的紧密集成。总体而言，该项目通过在相对紧凑和稳定的原子蒸气中，特别是在集成的纳米光子芯片规模的平台中，增加对便携式、频率敏捷性极强的非经典光源的访问，促进了量子传感方面的进步。该项目由量子传感器挑战量子系统变革性进展(QuSeC-TAQS)计划和国际科学与工程办公室共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.