Modification of excitation and charge transfer in cavity quantum-electrodynamical chemistry*

Energy transfer in terms of excitation or charge is one of the most
basic processes in nature and understanding and controlling them
is one of the major challenges of modern quantum chemistry. In this
work, we highlight that these processes as well as other chemical
properties can be drastically altered by modifying the vacuum fluctuations of the electromagnetic field in a cavity. By using a real-space formulation from first principles that keeps all the electronic degrees
of freedom in the model explicit and simulates changes in the environment by an effective photon mode, we can easily connect to well-known quantum-chemical results such as Dexter charge- and
Förster excitation-transfer reactions taking into account the often
disregarded Coulomb and self-polarization interaction. We find that
the photonic degrees of freedom introduce extra electron-electron
correlations over large distances, that the coupling to the cavity
can drastically alter the characteristic charge-transfer as well as the excitation energy transfer behavior. Our results highlight that changing the photonic environment can redefine chemical processes, rendering polaritonic chemistry a promising approach towards the control of chemical reactions.