Static Coherent States Method: One- and Two-Electron Laser-Induced Systems with Classical Nuclear Dynamics

Abstract

Featured Application: We present a new computational method that can be used to investigate the quantum dynamics of one-or two-electron systems during interaction with an ultrashort laser pulse, including nuclear dynamics. The inclusion of both electronic and nuclear degrees of freedom allows for a description of a wide range of processes, including charge migration during the nuclear dissociation process. Abstract:In this report, we introduce the static coherent states (SCS) method for investigating quantum electron dynamics in a one-or two-electron laser-induced system. The SCS method solves the time-dependent Schrödinger equation (TDSE) both in imaginary and real times on the basis of a static grid of coherent states (CSs). Moreover, we consider classical dynamics for the nuclei by solving their Newtonian equations of motion. By implementing classical nuclear dynamics, we compute the electronic-state potential energy curves of H + 2 in the absence and presence of an ultra-short intense laser field. We used this method to investigate charge migration in H + 2 . In particular, we found that the charge migration time increased exponentially with inter-nuclear distance. We also observed substantial charge localization for sufficiently long molecular bonds.

High‐order harmonic generation by static coherent states method in single‐electron atomic and molecular systems

“…Implementing the SCS method, 49 we construct a static grid of 3D CS in the phase space using a random Gaussian distribution function. In each dimension, the same number of 1D CS jzi are generated using…”

“…CS have been implementing during the last two decades as an advantageous basis set for solving 3D TDSE for high dimensional quantum systems in the presence of an ultra-short intense laser field. 45,[49][50][51][52][53][54][55][56] One of their beneficial characteristics is that their grid can be generated randomly. The major problem which other basis sets involves Coulombic potential singularities.…”

“…45,52,53 Such issues are tackled in SCS by using static grids of CS instead of trajectory-guided ones. 49 However, constructing an appropriate grid of SCS is challenging since we need enough CS distributed in the phase-space to cover the entire physical area needed for simulation. 49 The rest of the paper is organized as follows: first, we briefly review the main equations of the SCS method and formulate them to compute HHG.…”

“…49 However, constructing an appropriate grid of SCS is challenging since we need enough CS distributed in the phase-space to cover the entire physical area needed for simulation. 49 The rest of the paper is organized as follows: first, we briefly review the main equations of the SCS method and formulate them to compute HHG. We apply the SCS approach to compute HHG spectra of the Hydrogen molecular ion induced by a linearly polarized laser field.…”

“…Here, we employ static coherent state method (SCS) 49 for computing HHG in atomic and molecular systems. SCS method solves the 3D TDSE on the base of a static grid of coherent states (CS).…”