A theoretical perspective on molecular polaritonics

TL;DR

This paper reviews recent theoretical approaches to modeling molecular polaritons, emphasizing the complexity of light-matter interactions, vibrational spectra, and losses in realistic photonic environments.

Contribution

It provides a comprehensive perspective on advanced theoretical models for molecular polaritonics, highlighting challenges and recent developments.

Findings

Complex models are necessary for accurate polariton description

Vibrational spectra significantly influence polaritonic phenomena

Losses and dissipation must be incorporated into theoretical frameworks

Abstract

In the last decade, much theoretical research has focused on studying the strong coupling between organic molecules (or quantum emitters, in general) and light modes. The description and prediction of polaritonic phenomena emerging in this light-matter interaction regime have proven to be difficult tasks. The challenge originates from the enormous number of degrees of freedom that need to be taken into account, both in the organic molecules and in their photonic environment. On the one hand, the accurate treatment of the vibrational spectrum of the former is key, and simplified quantum models are not valid in many cases. On the other hand, most photonic setups have complex geometric and material characteristics, with the result that photon fields corresponding to more than just a single electromagnetic mode contribute to the light-matter interaction in these platforms. Moreover, loss and dissipation, in the form of absorption or radiation, must also be included in the theoretical description of polaritons. Here, we review and offer our own perspective on some of the work recently done in the modelling of interacting molecular and optical states with increasing complexity.