Positron Annihilation in Si and Ge

Abstract

Abstract A computational technique is developed to evaluate electron and electron—positron momentum densities in silicon and germanium and the use of these to provide means of interpreting the k ‐space densities obtained by experimentalis's using the two‐dimensional angular correlation of positron annihilation radiation technique (2D ACAR). As a consequence of the good agreement observed in the momentum densities and the LCW folded data obtained for silicon and germanium the independent particle approximation (IPM) coupled with the use of electron pseudo‐wavefunctions represent an excellent starting point for a systematic many‐particle description of the process, since significant deviations from the experimental angular correlation distribution can be ascribed to the electron—positron and electron—electron interactions.