Modulations to molecular high order harmonic generation by electron de Broglie wave

TL;DR

This paper introduces a new theory explaining how molecular internal symmetry and electron momentum distribution influence high order harmonic generation in molecules under intense laser fields, aligning well with experimental data.

Contribution

The paper proposes a novel theoretical framework linking molecular symmetry and electron de Broglie waves to harmonic generation modulation, advancing understanding of molecular HHG processes.

Findings

Suppression of adjacent harmonic orders observed.

Harmonic generation depends on laser intensity and molecular alignment.

Theoretical results match experimental observations.

Abstract

We present a new theory that the molecular high order harmonic generation in an intense laser field is determined by molecular internal symmetry and momentum distribution of the tunneling-ionized electron. The molecular internal symmetry determines the quantum interference form of the returning electron inside the molecule. The electron momentum distribution determines the relative interference strength of each individual electron de Broglie wave. All individual electron de Broglie wave interferences add together to collectively modulate the molecular high harmonic generation. We specifically discuss the suppression of the generation on adjacent harmonic orders and the dependence of molecular high harmonic generation on laser intensities and molecular axis alignment. Our theoretical results are in good consistency with the experimental observations.