Ab initio quantum electrodynamics: light-matter interactions from first principles

by Dr Michael Ruggenthaler (Max Planck Institut Hamburg)

Tuesday 5 Mar 2024, 14:00 → 15:00 Europe/Zurich

OVGA/200

In the last decade a host of seminal experimental results have demonstrated that properties and dynamics of molecules and solids can be modified and controlled by coupling strongly to the electromagentic field of a photonic environment, e.g. an optical cavity.

In this talk I will discuss the fundamental setting of ab initio quantum electrodynamics, the Pauli-Fierz quantum field theory in Coulomb gauge, highlight subtle yet important issues, e.g., the significance of the bare masses of the particles, and introduce a hierachy of approximations in first-principles approaches to light-matter coupled systems. I will introduce quantum-electrodynamical density-functional theory and cavity Born-Oppenheimer approaches and show results obtained with these first-principle methods. Among others I will highlight how collective strong coupling can imply local strong coupling, how we can potentially change ultra-cold chemistry and how equilibrium properties of materials might be modified by coupling strongly to optical cavities.