Complex quantum network model of energy transfer in photosynthetic complexes

TL;DR

This paper introduces quantum phase factors into a network model of energy transfer in photosynthetic complexes, revealing their crucial role in optimizing transfer efficiency through quantum interference and structural factors.

Contribution

It demonstrates that quantum phase factors, combined with pigment spacing and multiple pathways, significantly enhance energy transfer efficiency in photosynthetic complexes.

Findings

Quantum phase factors influence energy transfer dynamics.

Optimal pigment spacing maximizes transfer efficiency.

Multiple pathways and phase coherence enable near-perfect energy transfer.

Abstract

The quantum network model with real variables is usually used to describe the excitation energy transfer (EET) in the Fenna-Matthews-Olson(FMO) complexes. In this paper we add the quantum phase factors to the hopping terms and find that the quantum phase factors play an important role in the EET. The quantum phase factors allow us to consider the space structure of the pigments. It is found that phase coherence within the complexes would allow quantum interference to affect the dynamics of the EET. There exist some optimal phase regions where the transfer efficiency takes its maxima, which indicates that when the pigments are optimally spaced, the exciton can pass through the FMO with perfect efficiency. Moreover, the optimal phase regions almost do not change with the environments. In addition, we find that the phase factors are useful in the EET just in the case of multiple-pathway. Therefore, we demonstrate that, the quantum phases may bring the other two factors, the optimal space of the pigments and multiple-pathway, together to contribute the EET in photosynthetic complexes with perfect efficiency.