Topological aspects of cavity-induced degeneracies in polyatomic molecules

Conical intersections are degeneracies between multidimensional potential energy surfaces of molecular systems. It is well known that, besides these phenomena significantly modify the spectroscopic and dynamical properties of molecules, their presence in a molecular system has noticeable topological implications, as well. Such a consequence is the appearance of the topological or geometric phase. Conical intersections not only occur in nature but they can also be created by light. This can either be classical laser light or quantum light in an optical cavity. As a showcase example, by placing the formaldehyde (H2CO) molecule into a cavity, the topological properties (e.g., geometric or Berry phase) of the emerging light-induced conical intersection have been investigated for different cavity parameters and geometrical arrangements.