Footprints of electron correlation in strong-field double ionization of Kr close to the sequential-ionization regime

Abstract

With combination of kinematically complete measurement and semiclassical Monte Carlo simulation we study the correlated electron dynamics in strong field double ionization of Kr from nonsequential double ionization (NSDI) plateau to sequential double ionization (SDI) domain. In the NSDI regime, the measurements on Kr show consistent crossover behavior in comparison with early results on Ar and Xe, reveal the complex competition between the screening effect of inner-shell electrons and the Coulomb focusing of nuclei. In the SDI regime, we find that the electron correlation still gets involved in a subtle way.

Longitudinal momentum of the electron at the tunneling exit

“…Since the tunneling exit is defined as the point where the kinetic energy vanishes (the potential energy equals the total energy), at first glance from the classical perspective, one may simply think that the electron momentum is zero. Some versions of the semiclassical model still assume this zero-longitudinal-momentum condition [35][36][37][38][39].…”

“…At turning points, for example a tunneling exit point x e , E = V (x e ), so p cl (x e ) = 0. This is the argument based on which the tunneling exit momentum was assumed to be zero in semiclassical trajectory models [35][36][37][38][39]. Substituting ψ(x) = A(x)e iφ(x) into Eq.…”

“…At first glance from a classical perspective, this tunneling-exit momentum should not be a problem at all: At the tunneling exit point the kinetic energy of the electron is zero (since the potential energy equals to the total energy) therefore the momentum should be zero. Indeed, several versions of the semiclassical trajectory models [35][36][37][38][39] still assume the longitudinal momentum to be zero based on this classical argument. * Electronic address: xwang@gscaep.ac.cn However, recent experiments have found that assuming the longitudinal momentum to be zero does not yield good agreements between theoretically simulated and experimentally measured electron momentum distributions [26,29,33].…”

Femtosecond strong-field coherent control of nonresonant ionization with shaped pulses

“…The total ionization yield and kinetic energy distribution of electrons are measured by a cold-target recoil-ion-momentum spectrometer (COTRIMS). [27] First, we measure the ionization yield and kinetic energy distribution of electrons using shaped pulse sequences with varying polarization, as functions of sinusoidal parameters T and φ . Then we investigate the effect of polarization changing on the ionization yield and kinetic energy distribution using a shaped pulse sequence with constant linear polarization.…”

Accurate in situ Measurement of Ellipticity Based on Subcycle Ionization Dynamics

“…The experimental setup [40] is depicted in Fig. 1, in which a linearly polarized 800 nm, 40 femtosecond laser pulse is divided into two arms using a 50% dielectric beam splitter.…”