Energy transfer properties and absorption spectra of the FMO complex: from exact PIMC calculations to TCL master equations

TL;DR

This study models excitonic energy transfer in the FMO complex using a TCL master equation validated by PIMC simulations, accurately reproducing experimental absorption spectra without fitting parameters.

Contribution

It introduces a TCL master equation approach validated by PIMC for modeling EET and absorption spectra in the FMO complex, with a novel application of Marcus' theory for Lindblad operators.

Findings

Good agreement with PIMC results for EET

Accurate reproduction of experimental absorption spectra

Model operates without fitting parameters

Abstract

We investigate the excitonic energy transfer (EET) in the Fenna-Matthews-Olsen complex and obtain the linear absorption spectrum (at 300 K) by a phenomenological time-convolutionless (TCL) master equation which is validated by utilizing Path Integral Monte Carlo (PIMC) simulations. By applying Marcus' theory for choosing the proper Lindblad operators for the long-time incoherent hopping process and using local non-Markovian dephasing rates, our model shows very good agreement with the PIMC results for EET. It also correctly reproduces the linear absorption spectrum that is found in experiment, without using any fitting parameters.