Density-based one-dimensional model potentials for strong-field simulations in He, H2+ , and H2

Abstract

We present results on the accurate one-dimensional (1D) modeling of simple atomic and molecular systems excited by strong laser fields. We use atomic model potentials that we derive from the corrections proposed earlier using the reduced ground state density of a three-dimensional (3D) single-active electron atom. The correction involves a change of the asymptotics of the 1D Coulomb model potentials while maintaining the correct ground state energy. We present three different applications of this method: we construct correct 1D models of the hydrogen molecular ion, the helium atom and the hydrogen molecule using improved parameters of existing soft-core Coulomb potential forms. We test these 1D models by comparing the corresponding numerical simulation results with their 3D counterparts in typical strong-field physics scenarios and we find an impressively increased accuracy in the dynamics of the most important atomic quantities on the time scale of the excitation. We also present the high-order harmonic spectra of the He atom, computed using our 1D atomic model potentials. They show a very good match with the structure and phase obtained from the 3D simulations in an experimentally important range of excitation amplitudes.

Diatomic molecule in a strong infrared laser field: level-shifts and bond-length change due to laser-dressed Morse potential

“…Although the theoretical framework for molecules interacting with laser fields is well established [23,24], analytic results are rare and usually approximate in the strong-field domain, while most of the numerical methods [1,[25][26][27] have heavily increasing cost for IR wavelength. Thus, new analytic methods for molecules in strong fields are of great significance.…”

Attoscience in phase space

“…Even in the single-electron regime, it is desirable to move from one-dimensional models. This interest ranges from a more accurate description of the dynamics [164,165] to studies in orthogonally polarised fields [217].…”

“…2.4. For one-electron problems, a discussion of how to keep the one-dimensional dynamics and observables as close as possible to a threedimensional system is given in [164,165].…”

Controlling quantum effects in enhanced strong-field ionisation with machine-learning techniques

“…( 3) provides qualitative insight into the behaviour of Coulomb potentials, which suffices for the objectives of the present work. Recently, however, the soft-core potential has been modified to exhibit quantitative agreement with realistic three dimensional models [76,77]. The external laser field is either taken to be static, that is E(t) = E 0 , or a timedependent linearly polarised polychromatic field such that…”