Dimerization-assisted energy transport in light-harvesting complexes

TL;DR

This study investigates how the dimer structure of light-harvesting complex II (LH2) influences excitation energy transfer efficiency and speed, using quantum open system models to analyze different initial quantum states.

Contribution

It demonstrates that dimerization in LH2 can enhance energy transfer efficiency and reduce transfer time, providing insights into the structural optimization of photosynthetic complexes.

Findings

Dimerization improves transfer efficiency.

Dimerization shortens transfer time.

Quantum superposition states affect transfer dynamics.

Abstract

We study the role of the dimer structure of light-harvesting complex II (LH2) in excitation transfer from the LH2 (without a reaction center (RC)) to the LH1 (surrounding the RC), or from the LH2 to another LH2. The excited and un-excited states of a bacteriochlorophyll (BChl) are modeled by a quasi-spin. In the framework of quantum open system theory, we represent the excitation transfer as the total leakage of the LH2 system and then calculate the transfer efficiency and average transfer time. For different initial states with various quantum superposition properties, we study how the dimerization of the B850 BChl ring can enhance the transfer efficiency and shorten the average transfer time.