On the Screening of Impurity Potential by Conduction Electrons

Abstract

A detailed investigation is made on self-consistent impurity potential in a charge cloud of conduction electrons. It is shown first that the Thomas-Fermi method can be used so as to include a certain correlation effect between the conduction electrons which is ignored in customary theories. The same problem is then treated by the method of Nakajima and Bardeen and Pines and it is shown that it leads to essentially the same result as that obtained by the Thomas-Fermi method. The obtained potential differs from the usual one in the fact that the screening parameter now depends on the way of the scattering. Some discussion is given about the equivalence of the two methods and further possible improvement. The potential thus derived is then used for the calculation of the electric resistance governed by the impurity scattering.