Energy transfer among distant quantum systems in spatially shaped laser fields: Two H atoms with the internuclear separation of 5.29 nm (100 a.u.)

TL;DR

This study numerically investigates energy transfer and ionization dynamics between two distant hydrogen atoms excited by ultrashort, spatially shaped laser pulses, revealing mechanisms of electron interaction and energy flow over large separations.

Contribution

It introduces a 3D quantum model for two distant hydrogen atoms under spatially shaped laser fields, demonstrating energy transfer mechanisms and ionization processes at large internuclear distances.

Findings

Efficient energy transfer from atom A to B observed.

Ionization of atom B can surpass that of atom A.

Different spatial laser profiles influence energy transfer and ionization mechanisms.

Abstract

The quantum dynamics of two distant H atoms excited by ultrashort and spatially shaped laser pulses is studied by the numerical solution of the non-Born-Oppenheimer time-dependent Schr\"odinger equation within a three-dimensional (3D) model, including the internuclear distance R and the two z coordinates of the electrons, z1 and z2. The two 1D hydrogen atoms, A and B, are assumed to be initially in their ground states with a large (but otherwise arbitrary) internuclear separation of R = 100 a.u. (5.29 nm). Two types of a spatial envelope of a laser field linearly po- larized along the z-axis are considered: (i) a broad Gaussian envelope, such that atom A is excited by the laser field predominantly, and (ii) a narrow envelope, such that practically only atom A is excited by the laser field. With the laser carrier frequency {\omega} = 1.0 a.u. and the pulse duration tp = 5 fs, in both cases an efficient energy transfer from atom A to atom B has been found. The ionization of atom B achieved mostly after the end of the laser pulse is close to or even higher than that of atom A. It is shown that with a narrow spatial envelope of the laser field, the underlying mechanisms of the energy transfer from A to B and the ionization of B are the Coulomb attraction of the laser driven electron by the proton of atom B and a short-range Coulomb repulsion of the two electrons when their wave functions significantly overlap in the domain of atom B. In the case of a broad Gaussian spatial envelope of the laser field, the opposite process also occurs, but with smaller probability: the energy is transferred from the weakly excited atom B to atom A, and the ionization of atom A is also induced by the electron-electron repulsion in the domain of atom A due to a strong overlap of the electronic wave functions.