Vibrational vs. electronic coherences in 2D spectrum of molecular systems

TL;DR

This paper presents a method to distinguish vibrational from electronic coherences in 2D spectra of molecular systems by analyzing phase and amplitude relationships of spectral oscillations.

Contribution

It introduces a novel analysis technique for interpreting 2D spectra to identify the nature of observed coherences in molecular systems.

Findings

Method successfully differentiates vibrational and electronic coherences.

Analysis applied to two representative molecular systems.

Provides a clearer understanding of oscillatory behaviors in 2D spectra.

Abstract

The two-dimensional spectroscopy has recently revealed oscillatory behavior of excitation dynamics in molecular systems. However, in the majority of cases it is strongly debated if excitonic or vibrational wavepackets, or evidences of quantum transport have been observed. In this letter, the method for distinguishing between vibrational and excitonic wavepacket motion is presented, based on the phase and amplitude relationships of oscillations of distinct peaks, which has been revealed using fundamental analysis of two-dimensional spectrum of two representative systems.