抄録
On the basis of a simple model we discuss how impurity atoms can be paramagnetic in semiconductors. The model is a system of two interacting electrons in the conduction band of a semiconductor containing a single donor-type impurity. The band structure is assumed to be such that the corresponding density of states curve has a semi-elliptic form. This band structure is an approximation to that of a real three-dimensional crystal. The problem is formulated in terms of one-electron Green’s functions and is solved exactly. The results are qualitatively similar to those obtained by Mattis and Lieb, who exactly solved the same problem in the one-dimensional case. The present solution will be applicable to some two-electron problems associated with deep impurity states in semiconductors.
