Heterodyne Two-Dimensional Electronic Spectroscopy: Applications to Multilevel Molecular Systems and to Excitonic Molecular Aggregates

In the past few years, Two-Dimensional (2D) Spectroscopy has become one of the major tools for studying molecular dynamics in the condensed phase. 2D Electronic Spectroscopy has unraveled new energy flow pathways in photosynthetic light harvesting complexes as well as the dynamics of excitons in nanostructures. 2D Vibrational Spectroscopy has been applied to recovering the dynamics of the structural change in proteins as well as to the structure of protein aggregates. The molecular information in the 2D Spectroscopy is recovered from detailed analysis of the 2D spectra. This book links specific features in the 2D spectra to the physical processes in molecular systems. The theory involved and the phase-stabilized heterodyne experimental techniques are described in details. 2D spectral signatures of the energy gap fluctuations between the 1st and the 2nd excited states are demonstrated for a generic 3-level system. Heterogeneous dynamics is studied on the example of J-aggregates, excitonic molecular aggregates, which perfectly model photosynthetic light harvesting complexes, protein secondary structures, as well as protein aggregates.