Molecule-photon interactions in phononic environments

Abstract

Molecular spectroscopy in the solid-state crucially depends on the interaction of electronic degrees of freedom with a highly complex vibrational environment. The large number of intramolecular vibrations (vibrons) and crystal vibrations (phonons) have often reduced the analysis of these driven molecular systems to a limited set of vibrations and numerical studies. We describe the non-equilibrium dynamics of light-matter systems comprised of guest molecules hosted in crystalline environments including finite thermal occupancies of vibrons and phonons. Using an open-system approach based on quantum Langevin equations, we provide analytical expressions for absorption and emission spectra with arbitrary numbers of vibronic and phononic modes. Exploiting the potential of this framework, we find that vibron-phonon coupling leads to a generally non-Markovian vibrational relaxation dynamics and that the common coupling to phonons can mediate collective vibron-vibron interactions similar to the processes of sub-and superradiance for radiative transitions. For molecular polaritonic scenarios with a strongly confined quantum light mode, we analytically characterize the imprint of vibronic and phononic couplings onto the cavity transmission profile and derive effective polariton cross-talk rates for finite baths occupancies.

Plasmonic Purcell Effect in Organic Molecules

“…As a consequence, none of the simplified models used up to date are able to provide a precise estimation of near-or far-field emission spectra in hybrid systems involving organic molecules and plasmonic cavities. As an interesting extension of the current work, the influence of non-linear vibrational mode couplings leading to vibrational energy redistribution could be investigated, as they are not included in the current Holstein-type model and are expected to become important on slightly longer timescales than treated here [46,47]. Our findings also reveal that significant effective quantum yield values can be achieved in situations where strong interaction to non-radiative plasmonic modes takes place and quenching is expected to dominate.…”