Time-resolving electron-core dynamics during strong field ionization in circularly polarized fields

TL;DR

This paper introduces a quantum, time-dependent analytical method to analyze electron-core dynamics during strong-field ionization, revealing the physical significance of imaginary trajectory components and their impact on electron behavior.

Contribution

The study develops a novel analytical approach that incorporates imaginary trajectory components to accurately describe post-ionization electron-core interactions.

Findings

Imaginary parts of trajectories are physically meaningful and influence electron deceleration.

The method provides time-resolved electron energy distributions and ionization yields.

It clarifies when ionization is considered complete.

Abstract

Electron-core interactions play a key role in strong-field ionization and the formation of photoelectron spectra. We analyse the temporal dynamics of strong field ionization associated with these interactions using the time-dependent analytical R-matrix (ARM) method, developed in our previous work [J. Kaushal and O. Smirnova, Phys. Rev. A 88, 013421 (2013)]. The approach is fully quantum but includes the concept of trajectories. However, the trajectories are not classical in the sense that they have both real and imaginary components all the way to the detector. We show that the imaginary parts of these trajectories, which are usually ignored, have a clear physical meaning and are crucial for the correct description of electron-core interactions after ionization. In particular, they give rise to electron deceleration, as well as dynamics associated with electron recapture and release. Our approach is analytical and time-dependent, and allows one to gain access to the electron energy distribution and ionization yield as a function of time. Thus we can also rigorously answer the question: when is ionization completed?