Multiscale cyclic dynamics in light harvesting complex in presence of vibrations and noise

TL;DR

This paper develops a new Lindblad Master equation framework to model multiscale exciton and electron dynamics in light harvesting complexes, incorporating vibrations, noise, and multi-exciton effects for a comprehensive understanding.

Contribution

It introduces a novel master equation approach that captures multi-exciton states and various dynamical effects in light harvesting, extending beyond single-exciton models.

Findings

Reproduces coherent and incoherent exciton dynamics with vibrations and noise.

Provides insights into energy and fluorescence currents under sunlight.

Models multiscale exciton-electron interactions in complex biological systems.

Abstract

Starting from the many-body Schr\"odinger equation, we derive a new type of Lindblad Master equations describing a cyclic exciton/electron dynamics in the light harvesting complex and the reaction center. These equations resemble the Master equations for the electric current in mesoscopic systems, and they go beyond the single-exciton description by accounting for the multi-exciton states accumulated in the antenna, as well as the charge-separation, fluorescence and photo-absorption. Although these effects take place on very different timescales, their inclusion is necessary for a consistent description of the exciton dynamics. Our approach reproduces both coherent and incoherent dynamics of exciton motion along the antenna in the presence of vibrational modes and noise. We applied our results to evaluate energy (exciton) and fluorescent currents as a function of sunlight intensity.