First principles approaches to excited states chemistry under strong light-matter coupling

In recent years, research at the interface of chemistry, material science, and quantum optics has surged and now opens new possibilities to study strong light-matter interactions at different limits [1]. In these limits, electrons, nuclei and photons have to be treated on the same quantized footing. Towards this goal, we have introduced a general time-dependent density-functional theory [2].

In this talk, we use a novel linear-response formulation [3] within a density-functional framework to study excited states of strongly light-matter coupled systems. We study how the potential-energy surfaces (PES) of a CO bond stretching in a formaldehyde molecule is modified and show the influence of strong light-matter coupling on avoided crossings. These results demonstrate the novel abilities to alter and open new chemical reaction pathways as well as to create new hybrid states of light and matter [4].

Our work opens an important new avenue in introducing ab initio methods to the nascent field of collective strong light-matter interactions.

[1] J. Flick, N. Rivera, P. Narang, Nanophotonics 7(9), 1479 (2018).
[2] J. Flick, P. Narang, PRL 121, 113002 (2018).
[3] J. Flick, D. Welakuh, M. Ruggenthaler, H. Appel, A. Rubio, ACS Photonics (2019).
[4] J. Flick, P. Narang arXiv:1907.04646 (2019).