EXCITON TRANSPORT IN DYNAMICALLY DISORDERED MOLECULAR AGGREGATES - INFLUENCE ON OPTICAL-LINE SHAPES

For Frenkel excitons moving on a linear trimer we investigate the infl uence of dynamic disorder on their optical line shapes. The dynamic di sorder models the influence of vibrational degrees of freedom and is t aken into account by fluctuations of the local excitation energy and o f the transfer matrix element between neighbouring molecules. The fluc tuations are represented by dichotomic Markov processes with coloured noise. We obtain a closed set of equations of motion for the correlati on functions determining the optical line shape which is solved exactl y as well as using various approximations. The line shapes are discuss ed for various sets of the model parameters. Furthermore we show that slower fluctuations need higher approximations in our factorization sc heme. The limit of static fluctuations can only be covered by the full set of equations.