Microscopic theory of vibronic dynamics in linear polyenes

TL;DR

This paper introduces a new microscopic model combining Hubbard and electron-phonon interactions to describe ultrafast vibronic dynamics in linear polyenes, successfully matching experimental spectra.

Contribution

It presents a novel theoretical framework that integrates electronic and vibrational motions for ultrafast molecular processes, emphasizing the role of bond length-dependent electron-phonon coupling.

Findings

Qualitative agreement with experimental time-resolved photoelectron spectra

Highlights importance of bond length dependence in non-adiabatic processes

Provides a microscopic basis for vibronic dynamics in polyenes

Abstract

We propose a novel approach to calculate dynamical processes at ultrafast time scale in molecules in which vibrational and electronic motions are strongly mixed. The relevant electronic orbitals and their interactions are described by a Hubbard model, while electron-phonon interaction terms account for the bond length dependence of the hopping and the change in ionic radii with valence charge. The latter term plays a crucial role in the non-adiabatic internal conversion process of the molecule. The time resolved photoelectron spectra are in good qualitative agreement with experiments.