Polaritonic chemistry: Manipulating molecules through QED effects in a cavity

Par Johannes Feist, Universidad Autonoma de Madrid

Mardi 16 Octobre,  14h00, Salle des séminaires (215), 2ème étage, Bâtiment A4N

Abstract :

Traditional nanophotonics is concerned with engineering material systems to control light on a nanometer scale. However, over the last years, it has become clear that the reverse is also possible, i.e., to engineer light modes so as to modify material properties and dynamics. Remarkably, this can be achieved even when no actual light is present in the system by engineering the electromagnetic vacuum and its fluctuations, based on quantum electrodynamics (QED). The principal tool to achieve such modifications is so-called strong light-matter coupling, which occurs when the coherent energy exchange between a (confined) light mode and material excitations becomes faster than the decay and decoherence of either constituent. This creates a paradigmatic hybrid quantum system with eigenstates that have mixed light-matter character, so-called polaritons. Organic molecules present a particularly favorable type of emitter to achieve this regime even at room temperature due to their large dipole moments and stability. I will discuss how polariton formation leads to changes in the excited-state character and energy levels (i.e., potential energy surfaces), and how this can be used to modify static and dynamic properties, such as energy transport, photochemical reactions, and even thermally driven ground-state chemical reactions.