Coherent excitation energy transfer in model photosynthetic reaction center: Effects of non-Markovian quantum environment

TL;DR

This paper investigates how non-Markovian quantum environments influence excitation energy transfer in photosynthetic reaction centers, revealing extended coherence times and environmental effects that could inform organic photovoltaic device design.

Contribution

It introduces a mixed dynamic approach combining DEOM and Lindblad equations to study non-Markovian effects in photosynthetic energy transfer, advancing beyond traditional Markovian models.

Findings

Non-Markovian phonon baths extend coherence times to hundreds of femtoseconds.

Environmental manipulation affects current-voltage behavior in the model system.

Mixed DEOM-Lindblad simulations outperform purely Markovian or classical environment models.

Abstract

Excitation energy transfer (EET) and electron transfer (ET) are crucially involved in photosynthetic processes. In reality, the photosynthetic reaction center constitutes an open quantum system of EET and ET, which manifests an interplay of pigments, solar light and phonon baths. So far theoretical studies have been mainly based on master equation approaches in the Markovian condition. The non-Markovian environmental effect, which may play a crucial role, has not been sufficiently considered. In this work, we propose a mixed dynamic approach to investigate this open system. The influence of phonon bath is treated via the exact dissipaton equation of motion (DEOM) while that of photon bath is via the Lindblad master equation. Specifically, we explore the effect of non-Markovian quantum phonon bath on the coherent transfer dynamics and its manipulation on the current-voltage behavior. Distinguished from the results of completely Markovian Lindblad equation and those adopting classical environment description, the mixed DEOM-Lindblad simulations exhibit transfer coherence up to a few hundreds femtoseconds and the related environmental manipulation effect on current. These non-Markovian quantum coherent effects be extended tomore complex and realistic systems and be helpful to the design of organic photovoltaic devices.