Quantum interference in laser-induced nonsequential double ionization in diatomic molecules: the role of alignment and orbital symmetry

TL;DR

This paper investigates how molecular alignment and orbital symmetry affect interference patterns in laser-induced nonsequential double ionization of diatomic molecules, revealing how these factors influence electron momentum distributions and interference visibility.

Contribution

It introduces a detailed analysis of interference effects considering orbital symmetry and alignment, within the strong-field approximation and classical limits, highlighting their impact on electron momentum patterns.

Findings

Interference maxima and minima depend on molecular alignment and orbital symmetry.

Interference patterns are sharpest for molecules aligned parallel to the laser polarization.

Patterns diminish and disappear as the molecule's alignment shifts from parallel to perpendicular.

Abstract

We address the influence of the orbital symmetry and of the molecular alignment with respect to the laser-field polarization on laser-induced nonsequential double ionization of diatomic molecules, in the length and velocity gauges. We work within the strong-field approximation and assume that the second electron is dislodged by electron-impact ionization, and also consider the classical limit of this model. We show that the electron-momentum distributions exhibit interference maxima and minima due to the electron emission at spatially separated centers. The interference patterns survive the integration over the transverse momenta for a small range of alignment angles, and are sharpest for parallel-aligned molecules. Due to the contributions of transverse-momentum components, these patterns become less defined as the alignment angle increases, until they disappear for perpendicular alignment. This behavior influences the shapes and the peaks of the electron momentum distributions.