Long-Lived Electronic Coherences from First Principles

TL;DR

This paper presents a first-principles simulation method to understand and control long-lived electronic coherences in molecules, revealing how certain molecular states enable sustained electronic motions despite decoherence.

Contribution

It introduces a novel first-principles approach for simulating the creation and decay of electronic coherences in molecules, advancing understanding of long-lived electronic states.

Findings

Simulations show long-lived coherences in thiophene upon multiphoton excitation.

Coherent electronic motions are enabled by parallel potential energy surfaces of Rydberg states.

The approach helps explain experimental observations of electronic coherence lifetimes.

Abstract

Electronic coherences can be leveraged to control molecular dynamics, but such control is limited by ultrafast decoherence driven by coupling between electronic excitations and molecular vibrations. With the goal of understanding and controlling electronic coherence in molecules, we introduce a first-principles approach that enables direct simulation of the creation and decay of electronic coherences in molecules. Simulations of long-lived experimentally-observed coherences created upon multiphoton excitation of thiophene reveal coherent electronic motions within a dense manifold of Rydberg states, enabled by their relatively parallel potential energy surfaces.