Shallow Donor Electrons in Silicon. II. Considerations Regarding the Fermi Contact Interactions

Abstract
A detailed study of the Fermi contact interactions for ground-state shallow donor electrons in silicon has been carried out. This investigation was motivated by the recent experimental ENDOR measurements on arsenic, phosphorus, and antimony donors. Theoretical considerations are based on the existing Kohn-Luttinger formulation for these interactions. A number of figures are presented which graphically display various features of the theoretical model. Comparison of the theoretical and experimental results shows that the theory can only qualitatively account for the interactions and can not be used to predict uniquely most of the measured values. The analysis of the data also reveals several unexpected features in the wave-function structure.