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

University Of Maryland, College Park, College Park MD

Investigators

Abstract

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.