Non-perturbative calculation of 2D spectra in heterogeneous systems: Exciton relaxation in the FMO complex
Experimental 2D frequency resolved spectra showing the relaxation of excitons in the photosynthetic antenna system FMO are reproduced by a multi-exciton density matrix approach explicitly including the external fields. The interference of the polarizations of a number of randomly placed, rotated and energetically inhomogencous complexes is used to extract the signal in the phase matching direction
