Interference between direct and resonant channels in near-resonance photoemission in argon

Abstract

The wave nature of electrons, epitomized by Young's two-slit experiment, is also demonstrated in resonant photoemission. We present photoelectron spectra of argon measured in the vicinity of the ${2p}_{3/2}\ensuremath{\rightarrow}4s$ core excitation. Interference effects are monitored by following the intensity of final states populated through both the resonant and the direct channel. The partial-electron-yield spectra of ${3p}^{\ensuremath{-}2}\mathrm{nd}$ final states exhibit a rich variety of interference effects. This demonstrates the need for a unified one-step description of the ionization through a direct and a core-excitation mediated channel.