Atomistic study of the long-lived quantum coherences in the Fenna-Matthews-Olson complex

TL;DR

This study combines advanced simulation techniques to accurately model quantum coherence in the Fenna-Matthews-Olson complex, providing insights into its role in photosynthesis at an atomistic level.

Contribution

It introduces a comprehensive simulation approach integrating molecular dynamics, DFT, and open quantum systems to study quantum coherence in a biological complex.

Findings

Simulated population and coherence dynamics match experimental results.

Reproduced absorption and dichroism spectra at different temperatures.

Extended method to include vibrational zero-point fluctuations.

Abstract

A remarkable amount of theoretical research has been carried out to elucidate the physical origins of the recently observed long-lived quantum coherence in the electronic energy transfer process in biological photosynthetic systems. Although successful in many respects, several widely used descriptions only include an effective treatment of the protein-chromophore interactions. In this work, by combining an all-atom molecular dynamics simulation, time-dependent density functional theory, and open quantum system approaches, we successfully simulate the dynamics of the electronic energy transfer of the Fenna-Matthews-Olson pigment-protein complex. The resulting characteristic beating of populations and quantum coherences is in good agreement with the experimental results and the hierarchy equation of motion approach. The experimental absorption, linear and circular dichroism spectra and dephasing rates are recovered at two different temperatures. In addition, we provide an extension of our method to include zero-point fluctuations of the vibrational environment. This work thus presents one of the first steps to explain the role of excitonic quantum coherence in photosynthetic light-harvesting complexes based on their atomistic and molecular description.