Chemistry in Quantum Cavities: Exact Results in Thermal Equilibrium and Modified Dissociation¹

In recent years tremendous progress in the field of light-matter interactions has unveiled that strong coupling to an optical cavity can modify chemistry substantially. However, many fundamental questions of chemistry in cavities remain open today. This is also due to a lack of exact results that can be used to validate and benchmark approximate approaches. We provide, to our knowledge, the first exact numerical results for the Pauli-Fierz Hamiltonian of a three-body systems in 3D, coupled to one effective cavity mode. This allows us to investigate the reliability of the ubiquitous Jaynes-Cummings model not only for electronic but also for the case of ro-vibrational transitions of He, H₂⁺ and HD+. We show the emergence of new bound polaritonic states beyond the dissociation energy limit of H₂⁺ and we demonstrate the modification of chemical properties under thermal equilibrium conditions.

[1] Sidler, D.; Ruggenthaler, M.; Appel, H.; Rubio, A. J. Phys. Chem. Lett. 2020 (accepted), 10.1021/acs.jpclett.0c01556