Hydrogen atom in a Laser-Plasma

TL;DR

This paper investigates how hydrogen atom eigenvalues are affected by a laser-plasma environment with external electric fields, using the Kramers-Henneberger transformation and perturbation theory to model intense laser interactions.

Contribution

It introduces a laser-dressed potential model for hydrogen in plasma under external electric fields, expanding on previous methods with Fourier and Taylor series approximations.

Findings

Weak electric field and large Debye length lead to repulsive interactions.

Strong electric field and small Debye length cause attractive behavior.

The model can simulate atomic interactions in intense laser and plasma environments.

Abstract

We scrutinize the behaviour of hydrogen atom's eigenvalues in a quantum plasma as it interacts with electric field directed along $\theta=\pi$ and exposed to linearly polarized intense laser field radiation. Using the Kramers-Henneberger (KH) unitary transformation, which is semiclassical counterpart of the Block-Nordsieck transformation in the quantized field formalism, the squared vector potential that appears in the equation of motion is eliminated and the resultant equation is expressed in KH frame. Within this frame, the resulting potential and the corresponding wavefunction have been expanded in Fourier series and using Ehlotzky's approximation, we obtain a laser-dressed potential to simulate intense laser field. By fitting the exponential-cosine-screened Coulomb potential into the laser-dressed potential, and then expanding it in Taylor series up to $\mathcal{O}(r^4,\alpha_0^9)$, we obtain the eigensolution (eigenvalues and wavefunction) of hydrogen atom in laser-plasma encircled by electric field, within the framework of perturbation theory formalism. Our numerical results show that for a weak external electric field and gargantuan length of Debye screening parameter, the system is strongly repulsive in contrast for strong external electric field and small length of Debye screening parameter, the system is very attractive. This work has potential application in the areas of atomic and molecular processes in external fields including interactions with strong fields and short pulses.