Influence of coherent vibronic excitation on the high harmonics generation of diatomic molecules

TL;DR

This paper investigates how coherent vibronic excitations in diatomic molecules affect high harmonic generation spectra, revealing interference effects influenced by resonances with the driving laser field.

Contribution

It introduces a theoretical framework using time-dependent density functional theory to analyze vibronic effects on HHG in molecules, highlighting novel interference structures.

Findings

Interference structures in HHG spectra depend on vibronic resonances.

Vibronic excitations can modulate the intensity and structure of high harmonics.

Resonance control offers new ways to manipulate HHG in molecules.

Abstract

The generation of high harmonics (HHG) in atomic systems by the highly non-linear response to an intense laser field is a prominent pathway to the synthesis of ever shorter laser pulses at increasingly higher photon energies. Extensions of this process to molecules add to the complexity but also offers novel opportunities as multi-center effects and the coupling to nuclear degrees of freedom can influence HHG. In this work we theoretically explore the impact of coherent vibronic excitations of diatomic molecules on the HHG spectrum within the framework of time-dependent density functional theory. We observe the appearance of novel interference structures in the HHG spectra controlled by resonances between the driving field and the vibronic wavepacket.