Modification of Molecular structure Under Strong Coupling to confined Light modES

2026-07-22

Understanding and controlling the properties of matter is one of the overarching goals of modern science. A powerful way to achieve is this by using light, usually in the form of intense laser beams. However, modern advances in nanophotonics allow us to confine light modes so strongly that their effect on matter is felt even when no external fields are present. In this regime of “strong coupling” or “vacuum Rabi splitting”, the fundamental excitations of the coupled system are hybrid light-matter states which combine the properties of both constituents, so-called polaritons. Little attention has been paid to the fact that strong coupling can also affect internal structure, such as nuclear motion in molecules. First experimental indications for this effect have been found, but current theory cannot explain or predict such changes. We will thus develop theoretical methods that can treat the modification of molecular structure under strong coupling to confined light modes. This will require advances in the microscopic description of the molecules under strong coupling by explicitly including their rovibrational degrees of freedom, as well as techniques to incorporate the influence of these modes in the macroscopic setting of collective strong coupling. In order to achieve this, we will adapt well-known techniques from quantum chemistry and combine them with the concepts of polariton physics. We will investigate what level of control can be gained through this approach, and whether confined light modes could act as a “photonic catalyst” to control molecular dynamics without requiring an active ingredient. This could present a novel tool to control photochemical reactions that are of paramount importance in the biological mechanisms of vision and photosynthesis, and hold great interest for use in memories, photoswitching devices, light-driven actuators, or solar energy storage. Consequently, this work could have wide-ranging impact on many different fields of science.

Spain

2026-01-15