Intra- and intercycle interference of electron emission in laser assisted XUV atomic ionization

TL;DR

This paper investigates the complex interference patterns in electron emission during laser-assisted XUV atomic ionization, combining semiclassical, quantum, and ab initio methods to analyze how these patterns depend on pulse timing and intensity.

Contribution

It introduces a semiclassical model linking emission times to electron energies and compares it with advanced quantum simulations, enhancing understanding of interference effects in ionization.

Findings

Intercycle and intracycle interference patterns are identified and characterized.

The semiclassical model accurately predicts interference structures.

Interference patterns vary with pulse delay and laser intensity.

Abstract

We study the ionization of atomic hydrogen in the direction of polarization due to a linearly polarized XUV pulse in the presence a strong field IR. We describe the photoelectron spectra as an interference problem in the time domain. Electron trajectories steming from different optical laser cycles give rise to intercycle interference energy peaks known as sidebands. These sidebands are modulated by a grosser structure coming from the intracycle interference of the two electron trajectories born during the same optical cycle. We make use of a simple semiclassical model which offers the possibility to establish a connection between emission times and the photoelectron kinetic energy. We compare the semiclassical predictions with the continuum-distorted wave strong field approximation and the ab initio solution of the time dependent Schr\"odinger equation. We analyze such interference pattern as a function of the time delay between the IR and XUV pulse and also as a function of the laser intensity.