Dynamics of primary charge separatiion in bacterial photosynthesis using the multievel redfield-davies secular approach

摘要

We use Redfield's relaxation theory in the Davies Formulation to study primary charge separation reactions in bacterial photosynthesis.The specific model studied is the standard one(spin-boson),with three states for the system,harmonic oscillators for the bath,and linear ohmic system-bath coupling.The Redfield-Davies formulation,which is equivalent to the secular approximation,is Markovian,of second order in system-bath coupling,and is written for the system's density matric.The approximation does not suffer from any negative probabilities(which appear in the original Redfield approach)and can there fore be used for long-trime processes(20ps or more here).Our results are in line with previous studies.especially to high bath frequencies.They confirm the usefulness of the redfield-Davies secular approach as a convenient and simple tool for studying system-bath processes.