A 4-Component Dirac Theory of Ionization of Hydrogen Molecular Ion in a Super-Intense Laser Field

TL;DR

This paper develops a relativistic 4-component Dirac theory for hydrogen molecular ion ionization under super-intense laser fields, deriving analytic expressions for spin-specific and total ionization currents, and exploring relativistic effects like interference and spin control.

Contribution

It introduces a novel relativistic Dirac framework for molecular ionization in intense laser fields, extending non-relativistic results to include spin and interference effects.

Findings

Molecular two-slit interference persists in relativistic regime

Spin-flip ionization currents are significant and calculable

Control of spin currents via laser polarization is possible

Abstract

In this paper a 4-component Dirac theory of ionization of hydrogen molecular ion in a super-intense laser field is developed. Simple analytic expressions for the spin specific as well as the total ionization currents emitted from the ground state of the ion are derived. The results are given for all polarization and finite propagation vectors of the field. They apply for inner-shell ionization of analogous heavier molecular ions as well. The presence of molecular two-slit interference effect, first found in the non-relativistic case, and the spin-flip ionization current, and an asymmetry of the up- and down-spin currents similar to that predicted in the atomic case, are found also to hold for the present relativistic molecular ionic case. Finally, the possibility of controlling the dominant spin currents by selecting the handedness of a circularly polarized incident laser field is pointed out.