Radiation-field-driven ionization in laser-assisted slow atomic collisions

TL;DR

This paper demonstrates that radiation-field coupling significantly influences ionization in slow atomic collisions, especially at higher velocities, challenging the assumption that such effects are negligible in these processes.

Contribution

It reveals the importance of radiation-field coupling in ionization during slow atomic collisions, highlighting its increasing relevance with higher collision velocities and the potential dominance of Breit interaction.

Findings

Radiation-field coupling affects ionization in slow atomic collisions.

The effect becomes more significant as collision velocity increases.

Breit interaction can dominate over Coulomb interaction at low energies.

Abstract

It is generally assumed that for ionization processes, which occur in slow atomic collisions, the coupling of the colliding system to the quantum radiation field is irrelevant. Here we show, however, that -- contrary to expectations -- such a coupling can strongly influence ionization of a beam of atomic species A slowly traversing a gas of atomic species B excited by a weak laser field. Moreover, this coupling becomes even more important when the collision velocity increases, getting comparable or exceeding the typical electron orbiting velocities in A and B. Our results imply furthermore that the Breit interaction can, in fact, dominate over the Coulomb interaction at very low energies.