Above-threshold ionization with highly-charged ions in super-strong laser fields: I. Coulomb-corrected strong field approximation

TL;DR

This paper develops a Coulomb-corrected strong field approximation to better understand above-threshold ionization in super-strong laser fields with highly charged ions, incorporating Coulomb effects perturbatively.

Contribution

It introduces a Coulomb correction to the strong field approximation using the eikonal approach, applicable in the nonrelativistic regime for highly charged ions.

Findings

Coulomb effects significantly influence ionization dynamics.

The formalism aligns with the Perelomov-Popov-Terent'ev method.

Applicable to both velocity and length gauges.

Abstract

Aiming at the investigation of above-threshold ionization in super-strong laser fields with highly charged ions, we develop a Coulomb-corrected strong field approximation (SFA). The influence of the Coulomb potential of the atomic core on the ionized electron dynamics in the continuum is taken into account via the eikonal approximation, treating the Coulomb potential perturbatively in the phase of the quasi-classical wave function of the continuum electron. In this paper the formalism of the Coulomb-corrected SFA for the nonrelativistic regime is discussed employing velocity and length gauge. Direct ionization of a hydrogen-like system in a strong linearly polarized laser field is considered. The relation of the results in the different gauges to the Perelomov-Popov-Terent'ev imaginary-time method is discussed.