Exciton dynamics and Quantumness of energy transfer in the Fenna-Matthews-Olson complex

TL;DR

This study provides numerically exact insights into quantum coherence and energy transfer in the Fenna-Matthews-Olson complex, highlighting the role of superposition states in the process.

Contribution

It introduces a detailed quantum dynamical analysis including vibrational fluctuations, revealing the superposition nature of energy transfer in the complex.

Findings

Coherence times are shorter than experimental observations.

Energy transfer occurs via Schrödinger-cat-like superpositions.

Quantified the 'quantumness' of energy transfer.

Abstract

We present numerically exact results for the quantum coherent energy transfer in the Fenna-Matthews-Olson molecular aggregate under realistic physiological conditions, including vibrational fluctuations of the protein and the pigments for an experimentally determined fluctuation spectrum. We find coherence times shorter than observed experimentally. Furthermore we determine the energy transfer current and quantify its "quantumness" as the distance of the density matrix to the classical pointer states for the energy current operator. Most importantly, we find that the energy transfer happens through a "Schr\"odinger-cat" like superposition of energy current pointer states.