Efficient simulation of three-pulse photon-echo signals with application to the determination of electronic coupling in a bacterial photosynthetic reaction center.
A time-nonlocal quantum master equation coupled with a perturbative scheme to evaluate the third-order polarization in the phase-matching direction k(s) = -k(1) + k(2) + k(3) is used to efficiently simulate three-pulse photon-echo signals. The present method is capable of describing photon-echo peak shifts including pulse overlap and bath memory effects. In addition, the method treats the non-Markovian evolution of the density matrix and the third-order polarization in a consistent manner, thus is expected to be useful in systems with rapid and complex dynamics. We apply the theoretical method to describe one- and two-color three-pulse photon-echo peak shift experiments performed on a bacterial photosynthetic reaction center and demonstrate that, by properly incorporating the pulse overlap effects, the method can be used to describe simultaneously all peak shift experiments and determine the electronic coupling between the localized Q(y) excitations on the bacteriopheophytin (BPhy) and accessory bateriochlorophyll (BChl) in the reaction center. A value of J = 250 cm(-1) is found for the coupling between BPhy and BChl.
Cheng
Yuan-Chung
YC
Department of Chemistry and QB3 Institute, University of California Berkeley, Berkeley, California 94720, USA.
Lee
Hohjai
H
Fleming
Graham R
GR
D001429:Bacteriochlorophylls / Q000737:chemistry; D004583:Electrons; D008954:Models, Biological; D010674:Pheophytins / Q000737:chemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D011789:Quantum Theory; D012242:Rhodobacter sphaeroides / Q000737:chemistry
D001429:Bacteriochlorophylls; D010674:Pheophytins; D045322:Photosynthetic Reaction Center Complex Proteins; C006678:bacteriopheophytin