Exploring Molecule-Cavity Interaction - A New Quantum Chemistry Model

Researchers at Fysikum have introduced a new model that blends quantum electrodynamics and quantum chemistry to simulate interactions of molecules with optical cavities. The team, led by Associate Professor Markus Kowalewski, delved into the domain of molecular polaritons—resultant entities when molecules interact with confined light modes in nano-cavities. Their study used the Hartree-Fock ansatz, a staple in quantum chemistry, to analyze the behavior of diatomic hydrogen fluoride molecules in an optical cavity. The newly established method, named cavity Born-Oppenheimer Hartree-Fock (CBO-HF), detected a unique mechanism involving cavity-mediated dipole-dipole interactions. This mechanism underlines how local changes can influence an entire molecular ensemble. Their findings also offer an explanation for observed alterations in chemical reactivity within nano-cavities. Furthermore, the CBO-HF model sets the stage for more intricate electronic structure calculations and the possibility of performing detailed simulations of molecular assemblies coupled to cavities.