2013/11/13 by Václav Perlík, Craig Lincoln, František Šanda +1 · 1 citation
Physics and Astronomy · #physics.chem-ph
paper · pdf · doi:10.1021/jz402468c
15 pages, 5 figures
arxiv created 2013/11/13 · arxiv updated 2017/08/31
Long-lived oscillations in 2D spectra of chlorophylls are at the heart of an ongoing debate. Their physical origin is either a multi-pigment effect, such as excitonic coherence, or primarily stems from localized vibrations. In the present work, we analyze distinguishing characteristics of relative phase difference measured between diagonal- and cross-peak oscillations. While direct discrimination between the two scenarios is obscured when peaks overlap, their sensitivity to temperature provides a stronger argument. We show that vibrational (vibronic) oscillations change relative phase with temperature, while electronic oscillations are only weakly dependent. This highlights that studies of relative phase difference as a function of temperature provide a clear and easily accessible method to distinguish between vibrational and electronic coherences.