Relativistic quantum theory of high harmonic generation on atoms/ions by strong laser fields

TL;DR

This paper develops a relativistic quantum theory for high harmonic generation in atoms and ions driven by ultraintense laser fields, proposing a scheme to eliminate magnetic drift effects in plasma environments.

Contribution

It introduces a Dirac-equation-based relativistic quantum framework for HHG and proposes a novel scheme involving underdense plasma and copropagating laser and ion beams.

Findings

Relativistic quantum theory for HHG derived from the Dirac equation.

Elimination of magnetic drift effects in high-intensity laser fields.

A new scheme for HHG in plasma environments using copropagating laser and ion beams.

Abstract

High-order harmonic generation (HHG) by hydrogenlike atoms/ions in the uniform periodic electric field, formed by the two linearly polarized counterpropagating laser beams of relativistic intensities, is studied. The relativistic quantum theory of HHG in such fields, at which the impeding factor of relativistic magnetic drift of a strong wave can be eliminated, is presented arising from the Dirac equation. Specifically, a scheme of HHG in underdense plasma with the copropagating ultraintense laser and fast ion beams is proposed.