Nondipole effects on the double-slit interference in molecular ionization by xuv pulses

TL;DR

This study explores how nondipole effects, specifically photon-momentum transfer and finite light speed, influence double-slit interference patterns in molecular ionization by XUV pulses, aiding in decoding ultrafast molecular dynamics.

Contribution

It provides a theoretical analysis of nondipole effects on molecular double-slit interference beyond the dipole approximation, highlighting the significance of interference minima in understanding photon-momentum transfer.

Findings

Photon-momentum transfer affects interference maxima but not minima.

Finite light speed influences interference patterns.

Interference minima are robust indicators for ultrafast molecular timing.

Abstract

The double-slit interference in single-photon ionization of the diatomic molecular ion $\mathrm{H}_2^+$ is theoretically studied beyond the dipole approximation. Via simulating and comparing the interactions of the prealigned $\mathrm{H}_2^+$ and the hydrogen atom with the xuv pulses propagating in different directions, we illustrate two kinds of effects that are encoded in the interference patterns of the photoelectrons from $\mathrm{H}_2^+$: (i) the photon-momentum transfer and (ii) the finite speed of light. While both effects could modify the maxima of the interference fringes, we show that the former one hardly affects the interference minima. Our results and analysis show that the interference minima rule out the influences of the photon-momentum transfer and, potentially, the multielectron effect, thus performing a better role in decoding the zeptosecond time delay for the pulse hitting one and the other atomic centers of the molecule.