Tensor Network simulation of polaron-polaritons in organic microcavities

TL;DR

This paper uses tensor network methods to simulate polaron-polaritons in organic microcavities, revealing how vibrational environments influence strong light-matter coupling and vibronic suppression.

Contribution

It extends existing models to include multiple vibrational modes and phononic baths, providing new insights into vibrational dressing and environmental effects in polaritonic systems.

Findings

Reduced vibrational dressing persists with many vibrational modes.

Environmental phononic properties significantly affect vibronic coupling.

Low-frequency environments suppress vibronic interactions more effectively.

Abstract

In the regime of strong coupling between molecular excitons and confined optical modes, the intra-molecular degrees of freedom are profoundly affected, leading to a reduced vibrational dressing of polaritons compared to bare electronically excited states. However, existing models only describe a single vibrational mode in each molecule, while actual molecules possess a large number of vibrational degrees of freedom and additionally interact with a continuous bath of phononic modes in the host medium in typical experiments. In this work, we investigate a small ensemble of molecules with an arbitrary number of vibrational degrees of freedom under strong coupling to a microcavity mode. We demonstrate that reduced vibrational dressing is still present in this case, and show that the influence of the phononic environment on most electronic and photonic observables in the lowest excited state can be predicted from just two collective parameters of the vibrational modes. Besides, we explore vibrational features that can be addressed exclusively by our extended model and could be experimentally tested. Our findings indicate that vibronic coupling is more efficiently suppressed for environments characterised by low-frequency (sub-Ohmic) modes.