Brownian simulation algorithm for the coherent optical excitation of electron-donor-acceptor complexes

A stochastic model of electron-donor-acceptor complex (EDAC) interacting coherently with a short laser pulse within the charge transfer band is considered in the low-field approximation. An analytical expression for the probability of detection the complex in the excited electronic state is obtained within the perturbation theory in the optical coupling parameter. New computational scheme for numerical simulations of coherent optical excitation in EDACs is proposed. This scheme extends the recrossing-algorithm of the Brownian simulation (RABS) method developed earlier for simulations of nonequilibrium electron transfer within the multimode Zusman/Jortner-Bixon model. The proposed algorithm implies calculations of stochastic trajectories of quasiparticles in multidimensional space of solvent coordinates, as well as transitions between different electronic and vibrational states of EDAC. Applicability conditions and efficiency of the algorithm are discussed.A stochastic model of electron-donor-acceptor complex (EDAC) interacting coherently with a short laser pulse within the charge transfer band is considered in the low-field approximation. An analytical expression for the probability of detection the complex in the excited electronic state is obtained within the perturbation theory in the optical coupling parameter. New computational scheme for numerical simulations of coherent optical excitation in EDACs is proposed. This scheme extends the recrossing-algorithm of the Brownian simulation (RABS) method developed earlier for simulations of nonequilibrium electron transfer within the multimode Zusman/Jortner-Bixon model. The proposed algorithm implies calculations of stochastic trajectories of quasiparticles in multidimensional space of solvent coordinates, as well as transitions between different electronic and vibrational states of EDAC. Applicability conditions and efficiency of the algorithm are discussed.