Study On Energy Transfer Efficiency In The Process Of Photosynthesis

The initial process of photosynthesis is divided into two steps: the first is to absorb sunlight through the light-harvesting complex;the second is to transfer the electron excitation to the reaction center(RC).The efficient energy transfer in this process has attracted a lot of attention in recent years.Research on photosynthesis energy transfer not only helps us understand the physical mechanism of photosynthesis,but also helps us to design artificially captured natural light systems and artificial light energy conversion devices to solve the problem of energy scarcity.In this paper,the decoherence effect of environmental noise on energy transfer is studied.Since the duration of this phase is very short,we believe that the quantum decoherence plays a major role,so this study does not consider the environmental damping effect over a long period of time.As an example,we will consider any three-site energy transfer in the Purple Bacterial Lighting-Harvesting Complex II(LHII)B850 loop as a simple model(referred to as the three-site system for short),and explore the quantum effect on energy in the presence or absence of ambient.The aim is try to get the energy transfer efficiency as a function of time.This paper used a solvable decoherence model which use analytic solutions to avoid errors in digital calculations.The following results were obtained:1.In this paper,the energy transfer efficiency in non-entangled pure state changes with time.In the presence of noisy environment,the initial energy transfer efficiency changes drastically with no stable value.Because of the quantum decoherence caused by noise after a long time,the value became stable.When there is no environmental impact,the transfer efficiency has been vibrating with time without a stable value.Therefore,noise can stabilize energy transfer and promote energy transfer efficiency.2.In our simulation only consider the interaction between environment and their systems.In the B850 ring,Each pigment molecule act as both a donor and a receptor,we only consider the interaction between dipole-dipole of adjacent pigment molecules and the interaction between pigment molecules and the environment.Through the research we know that in the initial process of photosynthesis,the energy transfer efficiency of a system is greatly increased with the increase of the excited states of a site and then tend to become stable after a long time.Meanwhile we can also guess that efficient energy transfer efficiency is closely related to molecular structure and quantum decoherence.