High harmonic generation by anions and atoms: effect of initial/final-state wavefunctions

Abstract

When high harmonic generation (HHG) is considered theoretically within the ideas of the rescattering mechanism, the specifics of initial/final state of an active electron usually attract little attention. We explore such specifics related to initial/final bound p-state of the active electron (existing studies concentrated on s-states). The halogen anions and noble gas atoms (except He) provide important examples of such targets. The present theory with realistic wavefunctions gives HHG rates by 1 or 2 orders of magnitude lower than previous calculations with asymptotic (single-exponential) wavefunctions. This indicates that the HHG process is much more sensitive to the description of the bound-state wavefunctions in the inner domain than the above-threshold ionization where the asymptotic (large-r) approach is sufficient and self-consistent. The rates of HHG processes with and without change of electron magnetic quantum number mℓ are compared for B(2p) and H(2p) targets.