title: Interference between competing pathways in atomic harmonic generation.
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 multielectron response we develop the 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.
authors.affiliation: Centre for Theoretical Atomic, Molecular and Optical Physics, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: A C
authors.initials: AC
authors.lastname: Brown
authors.forename: S
authors.initials: S
authors.lastname: Hutchinson
authors.forename: M A
authors.initials: MA
authors.lastname: Lysaght
authors.forename: H W
authors.initials: HW
authors.lastname: van der Hart