Optical signatures of coherence in molecular dimers

TL;DR

This paper investigates quantum correlations and cooperative emission signatures in molecular dimers interacting with vibrational environments, using experimental and theoretical tools to analyze photon coincidences under various conditions.

Contribution

It introduces a comprehensive model incorporating vibrational effects, disorder, and experimental limitations to better understand coherence in molecular dimers.

Findings

Photon coincidences remain resolvable despite disorder and environmental effects.

Projective measurements can induce cooperative signatures even with orthogonal emitter arrangements.

The polaron framework effectively models vibrational influences on quantum correlations.

Abstract

We calculate experimentally measurable signatures of quantum correlations in a coupled molecular dimer that strongly interacts with its vibrational environment. We investigate intensity and mode-resolved photon coincidences for different relative orientations of such dimers, and observe spatio-temporal correlations for various configurations. We find that projective measurements can produce cooperative signatures even when emitters are arranged orthogonal to each other. To model effects of vibrational environments that are present in realistic experimental situations, we use the polaron framework. Further, we also account for the effects of finite instrument response, varying temperature, and presence of static disorder. We analyse the effect of disorder in both dimer orientation and measurement direction and find that photon coincidences remain well-resolvable using state-of-the-art detectors. This work enhances our understanding of cooperative emission from two coupled emitters and offers direction for future experiments on probing their coherent dynamics.