Decomposition of the transition phase in multi-sideband RABBITT schemes

TL;DR

This paper investigates extending the asymptotic approximation in RABBITT schemes to multi-sideband setups, comparing theoretical predictions with ab initio calculations for atomic hydrogen to improve phase reconstruction accuracy.

Contribution

It introduces an extension of the asymptotic approximation to multi-sideband RABBITT schemes and validates it against time-dependent Schrödinger equation simulations.

Findings

The extended approximation agrees well with ab initio results.

It provides a more accurate phase analysis in multi-sideband RABBITT.

The method enhances understanding of multi-photon ionization processes.

Abstract

Reconstruction of Attosecond Beating By Interference of Two-photon Transitions (RABBITT) is a technique that can be used to determine the phases of atomic transition elements in photoionization processes. In the traditional RABBITT scheme, the so-called "asymptotic approximation" considers the measured phase as a sum of the Wigner phase linked to a single-photon ionization process and the continuum-continuum (cc) phase associated with further single-photon transitions in the continuum. In this paper, we explore the possibility of extending the asymptotic approximation to multi-sideband RABBITT schemes. The predictions from this approximation are then compared with results obtained by an {\it ab initio} calculation based on solving the time-dependent Schr\"odinger equation for atomic hydrogen.