title: Distinguishing Electronic and Vibronic Coherence in 2D Spectra by Their Temperature Dependence.
abstract: Long-lived oscillations in 2D spectra of chlorophylls are at the heart of an ongoing debate. Their physical origin is either a multipigment effect, such as excitonic coherence, or localized vibrations. We show how relative phase differences of diagonal- and cross-peak oscillations can distinguish between electronic and vibrational (vibronic) effects. 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.
authors: Institute of Physics, Faculty of Mathematics and Physics, Charles University , Ke Karlovu 5, Prague 121 16, Czech Republic.
authors: Václav
authors: V
authors: Perlík
authors: Photonics Institute, Vienna University of Technology , Gusshausstrasse 27, 1040 Vienna, Austria.
authors: Craig
authors: C
authors: Lincoln
authors: Institute of Physics, Faculty of Mathematics and Physics, Charles University , Ke Karlovu 5, Prague 121 16, Czech Republic.
authors: František
authors: F
authors: Sanda
authors: Photonics Institute, Vienna University of Technology , Gusshausstrasse 27, 1040 Vienna, Austria.
authors: Jürgen
authors: J
authors: Hauer