Polaritonic Quantum Chemistry

Eugene DePrince of Florida State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to develop theoretical tools for the description of strongly-coupled light-matter systems. Strong interactions between nanoconfined photons and molecular systems can lead to the creation of hybrid light-matter states, known as polaritons, that may display remarkably different chemical and physical properties than their parent components.

The technological and chemical applications of these polariton states are wide-ranging. Recent examples of cavity-based catalysis, polariton lasing, and plasmon-based photostabilization offer only a glimpse into the transformative potential of polaritonic approaches to chemistry and materials science. In order for the field to fully live up to its promise, the experimental realization of ultra-strong light-matter coupling must be accompanied by high-quality theoretical descriptions of the properties of polaritonic features.

The DePrince group will develop a robust, reliable, and systematically improvable framework for the ab initio description of polaritonic structure. The theories and software that will be developed will fill a gap in the existing computational tool kit for the high-accuracy description of polariton-mediated processes. Such tools have the potential to facilitate the rational design of new polariton-based technologies relevant to light harvesting, super conductivity, and quantum information science.

All software developed under this program will be released in a free and open-source manner. Under this award, the DePrince group also will be developing readily accessible online educational materials for quantum chemistry and computer science education.

Dr. DePrince and his team will take a many-body approach to the polaritonic structure problem, with an emphasis on the equation-of-motion (EOM) coupled-cluster (CC) hierarchy of methods. Polaritonic formulations of excitation-energy (EE), ionization potential (IP), and electron affinity (EA) EOM-CC theory and software will be developed and applied to a variety of problems involving cavity-bound molecules.

Ab initio descriptions of strong and ultra-strong light-matter coupling are rare, with only a few existing examples of many-body approaches to this problem having recently emerged. Given that the exact form of the electron-photon exchange-correlation functional in polaritonic formulations of density functional theory (DFT) is unknown, it appears that many-body methods such as the EOM-CC approaches that will be developed under this program offer the only route to universally reliable and systematically improvable descriptions of cavity-molecule interactions.

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.