# Vibration-assisted exciton transfer in molecular aggregates strongly coupled to confined light fields

## TL;DR

This study explores how vibrational modes influence exciton transfer in molecular aggregates strongly coupled to light, revealing conditions where vibrations enhance transport efficiency.

## Contribution

It explicitly includes exciton-vibration coupling in the open quantum dynamics model, extending prior simpler two-level system approaches.

## Key findings

- Vibration-assisted transfer occurs at strong exciton-cavity coupling matching vibrational frequency.
- Longer chains exhibit vibrational enhancement at ultrastrong coupling.
- Vibrational relaxation via phonon bath further facilitates exciton transport.

## Abstract

We investigate exciton transport through one-dimensional molecular aggregates interacting strongly with a cavity mode. Unlike several prior theoretical studies treating the monomers as simple two-level systems, exciton-vibration coupling is explicitly included in the description of open quantum dynamics of the system. In the framework of the Holstein-Tavis-Cummings model with truncated vibrational space, we investigate the steady-state exciton transfer through both a molecular dimer and longer molecular chains. For a molecular dimer, we find that vibration-assisted exciton transfer occurs at strong exciton-cavity coupling regime where the vacuum Rabi splitting matches the frequency of a single vibrational quanta. Whereas for longer molecule chains, vibration-assisted transfer is found to occur at the ultrastrong exciton-cavity coupling limit. In addition, finite relaxation of vibrational modes induced by the continuous phonon bath is found to further facilitate the exciton transport in vibrational enhancement regimes.