Theory of vibronic assistance in the nonequilibrium condensation of exciton polaritons in optically--pumped organic single crystal microcavities

TL;DR

This paper develops a reaction/diffusion model to understand how vibronic interactions facilitate the formation of exciton polariton condensates in optically pumped organic microcavities, highlighting the role of vibron reservoirs in lowering the condensation threshold.

Contribution

It introduces a novel coupled-field model incorporating vibron states, excitons, and polaritons to explain condensation mechanisms in organic microcavities.

Findings

Vibron reservoirs can increase exciton populations at finite temperature.

Presence of vibron states reduces the critical pumping threshold for condensation.

Model demonstrates the importance of vibronic effects in organic polariton systems.

Abstract

We present a reaction/diffusion model for the formation of a lower polariton condensate in a micro cavity containing an organic semiconducting molecular crystalline film. Our model--based upon an anthracene film sandwiched between two reflecting dielectric mirrors--consists of three coupled fields corresponding to a gas of excitons created by an external driving pulse, a reservoir of vibron states formed by the coupling between a ground-state vibrational model and a cavity photon, and a lower polariton condensate. We show that at finite temperature, the presence of the vibron reservoir can augment the exciton population such that a lower critical pumping threshold is required to achieve condensation.