Quantum pathways interference in laser-induced electron diffraction revealed by a semiclassical method

TL;DR

This paper introduces a semiclassical method combining the Herman-Kluk propagator with the strong-field approximation to accurately analyze electron trajectories and interference in laser-induced electron diffraction, enhancing ultrafast imaging techniques.

Contribution

A novel semiclassical approach that reveals multiple electron trajectories and interference effects in laser-induced electron diffraction, improving the understanding of electron dynamics in intense laser fields.

Findings

Multiple trajectories lead to the same final momentum, causing interference patterns.

Interference structures relate to laser-free electron-ion differential cross sections.

Method accurately reproduces photoelectron momentum distributions for atoms and molecules.

Abstract

We develop a novel method for strong-laser-field physics based on the combination of the semiclassical Herman-Kluk propagator and the strong-field approximation and demonstrate its high accuracy on the calculations of photoelectron momentum distribution (PMD) for atoms and molecules in intense lasers. For rescattered electrons, we show that for a given time that electron tunnels to the continuum, there are typically multiple trajectories that lead to the same final momentum in the high-energy region. These trajectories start with slightly different initial transverse momenta and carry different phases giving rise to the interference structures in the PMD, which can also be associated with the laser-free electron-ion differential cross section. This is in contrast to the well-known long and short trajectories, which result in different interference patterns. Our results can be used to extend current capabilities of the laser-induced electron diffraction and other ultrafast imaging and strong-field spectroscopic techniques.