Interference between competing pathways in harmonic generation

TL;DR

This paper studies how autoionizing resonances in argon influence fifth harmonic generation under laser fields, revealing interference effects between different electron responses using advanced time-dependent R-matrix theory.

Contribution

It introduces a new computational approach within time-dependent R-matrix theory to analyze multi-electron effects in harmonic generation.

Findings

Fifth harmonic yield shows asymmetric profiles due to interference effects.

Autoionizing resonances significantly modulate harmonic spectra.

Multi-electron responses are crucial for accurate harmonic generation modeling.

Abstract

We investigate the influence of the autoionizing 3s3p(6)nl resonances on the fifth harmonic generated by 200 - 240 nm laser fields interacting with Ar. To determine the influence of a multi-electron response we have developed capability within time dependent R-matrix theory to determine the harmonic spectra generated. The fifth harmonic is affected by interference between the response of a 3s electron and the response of a 3p electron, as demonstrated by the asymmetric profiles in the harmonic yields as functions of wavelength.