Coulomb-free and Coulomb-distorted recolliding quantum orbits in photoelectron holography

TL;DR

This paper analyzes various recolliding quantum orbits in Coulomb Quantum Orbit Strong-field Approximation, revealing new orbit types and interference patterns that improve agreement with ab-initio calculations for high-energy photoelectrons.

Contribution

It introduces a detailed classification of recolliding orbits in CQSFA, identifying overlooked interference effects and refining the understanding of photoelectron angular distributions.

Findings

Identification of new rescattered orbit types responsible for low-energy structures

Discovery of interference patterns caused by Coulomb-corrected backscattered orbits

Improved agreement with ab-initio methods for high-energy photoelectrons

Abstract

We perform a detailed analysis of the different types of orbits in the Coulomb Quantum Orbit Strong-field Approximation (CQSFA), ranging from direct to those undergoing hard collisions. We show that some of them exhibit clear counterparts in the standard formulations of the strong-field approximation for direct and rescattered above-threshold ionization, and show that the standard orbit classification commonly used in Coulomb-corrected models is over-simplified. We identify several types of rescattered orbits, such as those responsible for the low-energy structures reported in the literature, and determine the momentum regions in which they occur. We also find formerly overlooked interference patterns caused by backscattered, Coulomb-corrected orbits and assess their effect on photoelectron angular distributions. These orbits improves the agreement of photoelectron angular distributions computed with the CQSFA with the outcome of ab-initio methods for high-energy phtotoelectrons perpendicular to the field-polarization axis.