Correlated interaction fluctuations in photosynthetic complexes

TL;DR

This paper investigates how correlated fluctuations in interactions and energies within photosynthetic complexes affect their transport efficiency, revealing that these correlations can alter transfer rates and potentially enhance light harvesting.

Contribution

It provides the first quantitative analysis of correlations between interaction and energy fluctuations and their impact on photosynthetic efficiency.

Findings

Correlations influence transfer rates and population oscillations.

Interactions fluctuations significantly impact efficiency.

Correlations can lead to limited efficiency enhancement.

Abstract

The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown that these additional correlations typically lead to changes in interchromophore transfer rates, population oscillations and can lead to a limited enhancement of the light harvesting efficiency.