Photoelectron emission from LiF surfaces by ultrashort electromagnetic pulses

Abstract

Energy-and angle-resolved electron emission spectra produced by incidence of ultrashort electromagnetic pulses on a LiF(001) surface are studied by employing a distorted-wave method named the crystal surface-Volkov (CSV) approximation. The theory makes use of the Volkov phase to describe the action of the external electric field on the emitted electron, while the electron-surface interaction is represented within the tight-binding model. The CSV approach is applied to investigate the effects introduced by the crystal lattice when the electric field is oriented parallel to the surface plane. These effects are essentially governed by the vector potential of the external field, while the influence of the crystal orientation was found to be negligible.

A doubly distorted-wave method for atomic ionization by ultrashort laser pulses

“…In order to test the performance of the DDCV approach for multi-cycle pulses we evaluate photoelectron emission spectra for hydrogen atoms, comparing them with exact calculations obtained from the numerical solution of the TDSE in three spatial dimensions [23]. Our aim is to derive a simple and realistic method that allows us to extract information about the different ionization mechanisms and can be straightforwardly extended to more complex systems [24][25][26][27][28], for which the applicability of the TDSE becomes computationally prohibitive.…”

Interference in Floquet-Volkov transitions

“…Similar to Floquet states, a photoelectron may acquire additional photon energies and necessary momenta, and this phenomenon is called the laser-assisted photoemission effect (LAPE) [3,4]. It has been theoretically investigated by many authors [5][6][7][8], invoking the Volkov solution [9] which is an exact solution of the Klein-Gordon equation for a free electron in an infinite planar electromagnetic wave and, therefore, a special case of Floquet states for a free electron. LAPE may obscure the intrinsic dynamics of bound electrons (see below), but can be distinguished from the intrinsic dynamics by careful investigation [8].…”

Phase control of resonant tunneling in nanostructures

“…While electrons coming from the conduction band are initially in delocalized states, core electrons originate from the inner shells of solid ions, being initially concentrated around target nucleus. For the latter case one can apply the well‐known techniques developed for atoms, like for instance the strong field approximation , the direct numerical integration of the wave equation with a localized initial state or some model considerations . Such techniques are, however, not applicable for delocalized electrons from the conduction band, where different numerical methods have to be developed .…”