Functional Subsystems and Quantum Redundancy in Photosynthetic Light Harvesting

TL;DR

This study reveals that subsystems within the FMO complex can efficiently transfer energy, demonstrating quantum redundancy that enhances robustness and offers insights for designing advanced photovoltaic systems.

Contribution

It identifies and characterizes functional subsystems in the FMO complex that support efficient energy transfer with built-in quantum redundancy, a novel insight into photosynthetic efficiency.

Findings

Subsystems can transfer energy with efficiency matching or exceeding the full system.

Quantum redundancy provides protection against chromophore loss.

Detailed energy flow map within the FMO complex is provided.

Abstract

The Fenna-Matthews-Olson (FMO) antennae complex, responsible for light harvesting in green sulfur bacteria, consists of three monomers, each with seven chromophores. Here we show that multiple subsystems of the seven chromophores can transfer energy from either chromophore 1 or 6 to the reaction center with an efficiency matching or in many cases exceeding that of the full seven chromophore system. In the FMO complex these functional subsystems support multiple quantum pathways for efficient energy transfer that provide a built-in quantum redundancy. There are many instances of redundancy in nature, providing reliability and protection, and in photosynthetic light harvesting this quantum redundancy provides protection against the temporary or permanent loss of one or more chromophores. The complete characterization of functional subsystems within the FMO complex offers a detailed map of the energy flow within the FMO complex, which has potential applications to the design of more efficient photovoltaic devices.