This asymmetry is absent in Figure5b, corresponding to the linear superposition of electron and hole separate screenings, and clearly indicates that the dynamics of the hole screening is affected by the presence and movement of the emitted electron.
Hence, the effect associated with the hole screening becomes smaller for higher electron velocities.
Figure 3 Component of the cluster-induced force due to the hole screening.
In order to quantify the effect of the hole screening, we have calculated the energy loss of the photoelectron.
The higher is the energy of the photoemitted electron, the smaller is the effect induced by the hole screening.
This is related to the time the photoelectron spends in the neighborhood of the hole and to the characteristic time of the hole screening.
The value of Δ Eloss also shows that the effect of the hole screening is more significant the slower the electron.
Whenever the hole screening is taken into account, there is an acceleration force acting on the electron at the beginning of its trip.
The energy loss of the electron moving at 1 a.u. decreases almost by a factor of 2 when we include the hole screening in the process.
In the first approximation, in which the electron moves with constant velocity, we can conveniently identify the effect of the hole screening on the movement of the photoemitted electron.
