This project focuses on studying how molecules behave when they interact with light inside nanoscale optical cavities—tiny spaces that can trap light and enable strong light-matter interactions. Under these conditions, the interaction between light and molecules leads to the formation of hybrid particles called polaritons. The aim is to understand and control how these polaritons behave near exceptional points (EPs)—unique quantum phenomena where distinct quantum states merge in unconventional ways. Exceptional points offer powerful new routes for probing and manipulating quantum systems. By investigating how polaritons behave near EPs, novel methods for tuning molecular properties and enabling advanced applications in sensing, energy, and information technologies could be developed.

The planned work will impact DOE Basic Energy Sciences (BES) core research area towards understanding and developing novel materials with unique properties for Fundamental Science to Enable Clean Energy, and towards mimicking desirable properties and replacing materials for Fundamental Science to Transform Processing and Fabrication. The work advances fundamental understanding of molecular EPs, enabling precise quantum control over quantum states in molecular systems. Such control can provide new routes for tuning energy and charge transfer in molecular systems, aiding in the design of new molecular candidates for light harvesting and battery technologies. This directly addresses the DOE BES Chemical Sciences, Geosciences, and Biosciences (CSGB) research theme of Ultrafast Chemistry, and the Computational and Theoretical Chemistry (CTC) focus "on the accurate simulation and prescriptive design of correlated multi-electron and/or multi-photon energy transduction processes in field-driven complex open quantum systems requiring non-Hermitian dynamics approaches". Furthermore, the intricate topological behavior of molecular EPs makes them promising for quantum sensing applications. For example, EP-driven molecular quantum sensing could have a significant impact on monitoring chemical processes and enabling enantiomeric selectivity in chemical synthesis. These applications align with the CTC goal of exploiting coordinated effects of chirality, topology, and magneto-electric interactions to achieve novel functionalities. This work also addresses the CSGB theme on Charge Transport and Reactivity by providing a real-time understanding of polaritonic dynamics near EPs.

To achieve these goals, we will develop a groundbreaking simulation technique called NH-QED-TDCI. This new method will allow for the modeling of light-matter interactions in regimes previously beyond reach. NH-QED-TDCI will provide a theoretical foundation for designing molecule–cavity systems for exceptional point dynamics, enabling topological control over chemical processes with far-reaching implications. By leveraging the unique properties of exceptional points, scientists can unlock new ways to control chemical reactions, leading to next-generation sensors capable of detecting faint forces, fields, particles, or molecules. These capabilities are especially valuable for national security, environmental monitoring, and fundamental research in quantum physics and materials science. As the field grows, it holds the potential to revolutionize computing, communication, and materials design. Ultimately, this research will deepen our understanding of quantum-level light-matter interactions, laying the groundwork for advances in clean energy, precision sensing, and beyond.