Published: 15 January 2020, 10:31
In most cases when light-matter interactions are considered, a decoupling of light and matter is performed at the outset. Either the electromagnetic fields are prescribed and then properties of the matter subsystem are determined, as frequently found in e.g. quantum chemistry or solid-state physics, or the properties of matter are prescribed and then the evolution of the photon subsystem is determined, as done in, e.g., quantum optics or photonics. The backaction of the matter subsystem on the electromagnetic fields, and the subsequent effect of these modified fields on matter, and so on, is ignored.
In many recent experiments novel states of matter have been observed which question these traditional decoupling approximations. In the past years, we have therefore extended timedependent density-functional theory to include also the coupling to quantized photonfields . This allows to consider the self-consistent coupling of matter to photon field fluctuations. In the mean-field limit, this approach leads to coupled Ehrenfest Maxwell-Pauli-Kohn-Sham equations .
This talk is providing an overview of our recent work on strong light-matter coupling as, e.g. found in optical cavities, near nanostructures, or in tip enhanced spectroscopies. Examples are given how to use strong-light matter coupling to alter excitation energy and charge transfer, chemical reactions and transition states or harmonic generation and parametric down-conversion.
 M. Ruggenthaler et. al., Nature Reviews Chemistry, 3, 0118, 2018
 R. Jestaedt et. al., Advances in Physics, in press, 2019, arXiv: 1812.05049