Speaker
Dr
Heiko Appel
(Max Planck Institute for the Structure and Dynamics of Matter)
Description
In the second part of our presentation of QEDFT, we illustrate effects that appear in the strong-coupling regime of matter with cavity photons. In particular, we show how Born-Oppenheimer surfaces are modified in the presence of the cavity, discuss photon bound states, and analyze polariton splittings in molecular absorption spectra. As illustrated in part (I), the density-functional approach to quantum electrodynamics is formally an exact framework. Here we show by inversion of the exact many-body solution of the time-dependent Schrödinger equation for a quantum dot system the exact time evolution of the effective potential of the Maxwell-Kohn-Sham system in QEDFT and analyze this in terms of a cavity Born-Oppenheimer approximation. We compare these exact results with the first approximate functional of QEDFT which is based on an optimized-effective-potential approach for the coupled matter-photon system. To go beyond model systems, we introduce a Riemann-Silberstein formulation of Maxwell's equations and present the first ab-initio real-time propagations of the coupled Maxwell-Kohn-Sham equations for molecular systems.
