Shape resonances in photoionization cross sections and time delay

Abstract

Shape resonances in photoionization of atoms and molecules arise from a particular geometry of the ionic potential which traps the receding photoelectron in a quasi-bound state in a particular partial wave. This mechanism allows us to connect the photoionization cross section in the resonant region with the photoelectron scattering phase in this partial wave by a simple formula $\sigma \propto {\sin }^2{\delta }_{\ell }$. Due to this relation, the phase ${\delta }_{\ell }$ can be extracted from an experimentally known cross section and then converted to the photoelectron group delay (Wigner time delay) ${\tau }_{\mathrm{W}}=\partial {\delta }_{\ell }/\partial E$ which is measurable by recently developed laser interferometric techniques. Such a direct connection of the photoionization cross section and the time delay is a fundamental property of shape resonances which provides a comprehensive test of novel measurements against a large body of older synchrotron data.

arXiv comment6 pages, 4 figures

References in corpus (9)

• Attosecond delays in molecular photoionization
• Phase-resolved attosecond near-threshold photoionization of molecular nitrogen
• Attosecond timing of electron emission from a molecular shape resonance
• Electron Correlation Effects in Attosecond Photoionization of CO${}_2$
• Attosecond electron-spin dynamics in Xe 4d photoionization
• Influence of Shape Resonances on the Angular Dependence of Molecular Photoionization Delays
• Measuring the photoelectron emission delay in the molecular frame
• The Coulomb phase shift revisited
• Phase retrieval from angular streaking of XUV atomic ionization

Cited by in corpus (2)

• Relation Between Photoionisation Cross Sections and Attosecond Time Delays
• Resonant photoionization and time delay