On the origin of the cusp in the transverse momentum distribution for the process of strong field ionization

TL;DR

This paper explains the origin of the cusp in the transverse electron momentum distribution during strong field ionization, showing it results from Coulomb scattering states and can be described analytically.

Contribution

It introduces an analytical explanation for the cusp structure in TEMD based on Coulomb scattering states, independent of detailed ionization dynamics.

Findings

Cusp in TEMD arises from Coulomb scattering states.

Elementary cusps have a simple, universal structure.

Analytical description of the cusp structure is provided.

Abstract

We study the origin of the cusp-structure in the transverse or lateral electron momentum distribution (TEMD) for the process of tunelling ionization driven by a linearly polarized laser pulse. We show that appearance of the cusp in the TEMD can be explained as follows. Projection on the set of the Coulomb scattering states leads to appearance of "elementary" cusps which have simple structure as functions of the lateral momentum. This structure is independent of the detailed dynamics of the ionization process and can be described analytically. These "elementary" cusps can be used to describe the cusp-structure in TEMD.