In the first part a method for stochastic unraveling of general time-local quantum master equations (QME) which involve the reduced density operator at time t only is proposed. The present kind of jump algorithm enables a numerically efficient treatment of QMEs that are not of Lindblad form. So it opens large fields of application for stochastic methods. The unraveling can be achieved by allowing for trajectories with negative weight. We present results for the quantum Brownian motion and the Redfield QMEs as test examples. The algorithm can also unravel non-Markovian QMEs when they are in a time-local form like in the time-convolutionless formalism.
The second part of the lecture deals with a more specific application to the exciton transfer in the LH2 light-harvesting antenna complex of the purple bacteria Rhodospirillum molischianum. In a first step I will briefly describe how the spectral density for this system can be determined from a combination of molecular dynamics simulations with quantum chemistry calculations. In a second step I will (if time permits) describe how to calculate the anisotropy of fluorescence in such a light-harvesting complex and how this compares to experiment.