A PSEUDOPOTENTIAL CALCULATION FOR COMPTON PROFILE ANISOTROPY IN GAP

An empirical pseudopotential calculation has been carried out to study the anisotropy of Compton profiles between [100] and [111] directions of GaP. Compared to a purely local potential an l-dependent non-local potential is seen to explain the experimental anisotropy rather well. The contributions of the first and the second bands to the total measured anisotropy are found to cancel each other. This is found to be true even for Si. This means that the measured Compton profile anisotropies in compound and elemental semiconductors cannot be viewed in terms of the differences in the nature of the lowest band. Core-orthogonalization correction was found to have negligible effect on the Compton profiles.