Exciton Recombination in One-Dimensional Organic Mott Insulators

TL;DR

This paper develops a theoretical model explaining rapid exciton recombination in one-dimensional organic Mott insulators, emphasizing multi-phonon emission as the key mechanism, aligning with experimental observations and pressure dependence.

Contribution

It introduces a theory that accounts for fast recombination rates via multi-phonon processes in 1D organic Mott insulators, a novel explanation for experimental results.

Findings

Multi-phonon emission explains rapid recombination.

Coupling to phonons accounts for pressure dependence.

The theory matches pump-probe experimental data.

Abstract

We present a theory for the recombination of (charged) holons and doublons in one-dimensional organic Mott insulators, which is responsible for the decay of a photoexcited metallic state. Due to the charge-spin separation, the dominant mechanism for recombination at low density of charges involves a multi-phonon emission. We show that a reasonable coupling to phonons is sufficient to explain the fast recombination observed by pump-probe experiments in ET-F$_2$TCNQ, whereby we can also account for the measured pressure dependence of the recombination rate.