Spiral-like holographic structures: Unwinding interference carpets of Coulomb-distorted orbits in strong-field ionization

Abstract

We unambiguously identify, in experiment and theory, an overlooked holographic interference pattern in strong-field ionization, dubbed "the spiral," stemming from two trajectories where the potential and laser field are equally critical. Because of the strong interaction with the core of the two trajectories, the spiral could be employed as an optimal tool for probing the target after ionization and for revealing obfuscated phases in the bound states. We find that the spiral is responsible for interference carpets, formerly ascribed to direct trajectories, and that the carpet-interference condition is derived from the field symmetry. This case of mistaken identity may have prevented the spiral from being used as a holographic tool.

Dissecting subcycle interference in photoelectron holography

“…Restricting the ionization times but not the final propagation time allows physical processes that would be present in a real laser pulse and require multiple cycles, such as recollisions [50], to be approximated by the monochromatic theory, while removing the intercycle effects. This approach is an approximation to a real laser pulse, which neglects the laser envelope effects, but still can give very good agreement with experiment in the long-pulse case [15,16]. Note this is not the same as using a single-cycle top-hat laser pulse, which would introduce radical switch-on and switchoff effects in the electron dynamics.…”

“…Here we discuss the key aspects of the CQSFA required to understand the unit-cell averaging methods employed. The CQSFA has been explored in detail in previous publications [1,[9][10][11][12]15,16,32,33] (see Refs. [1,10,32] for key details and a review), therefore, only a brief overview related to the present work is provided.…”

“…These have been explained in detail in Refs. [1,[9][10][11][12]15,16,32,33] (see Ref. [12] for an implementation of all four orbits and Ref.…”

“…Photoelectron vector momentum distributions (PMDs) encode these trajectories as intricate interference patterns displayed in angularly resolved photoelectron measurements. Significant work has been applied towards isolating and disentangling these patterns in order to determine the electron [2,[5][6][7][8][9][10][11][12][13][14][15][16][17] and sometimes the core [18][19][20] dynamics.…”

“…It provides a very clear picture with four interfering "orbits," which may be switched on and off at will. This has enabled computationally fast and accurate analyses of experimental features [15,16].…”