Microscopic Aspects of Weak Light-Matter Coupling

V.A.G. Rivera, O. B. Silva, Yannick Ledemi +2 more

Anonymous

Simone De Liberato

In a recent paper, Bamba and Ogawa [Phys. Rev. A 88, 013814 (2013)] developed a microscopic model describing a photonic cavity coupled to an excitonlike resonance. One of the results they obtained studying such a model is that, in the ultrastrong coupling regime, dissipation rates calculated applying the rotating-wave approximation on the system-environment coupling qualitatively differ from the ones calculated using a microscopic theory based on the quantum electrodynamics for dielectric media. Here I show that this result is an artifact, caused by an inconsistent application of the rotating-wave approximation and by an unphysical parameter choice.

Vladislav Yu. Shishkov

Emission and absorption spectra of molecular films are impacted by low-frequency molecular vibrations. These vibrations define the linewidths of the absorption and emission spectral peaks, as well as the Stokes shift. In cavities that use a molecular film as an active medium, low-frequency molecular vibrations facilitate the thermalization of light, enabling the formation of Bose-Einstein condensation. In this work, I employ perturbation theory for Lindblad superoperators and derive the contribution of the low-frequency molecular vibrations to the thermalization rate of light in a weak coupling regime between light and matter. The derived thermalization rate applies for any cavity design but depends on the local microscopic properties of low-frequency molecular vibrations. I provide an estimation for the thermalization rate, which requires only knowledge of the macroscopic parameters of the system: light-matter interaction strength, resonant frequencies of the cavity and excitons, number of molecules in the illuminated area, and the linewidth temperature dependence of the 0-0 peak in the emission spectra of standalone molecular film.

Michael Ruggenthaler

Le Gouët