Single Impurity Scattering

Abstract

In this chapter we examine (using the techniques developed in Chap.4) a model hamiltonian describing the problem of a substitutional impurity in a perfect periodic lattice. The hamiltonian is given by H = H ₀ + H ₁ where H ₀ is a periodic TBH of the type studied in Chap.5 and H ₁ describes the change of the potential as a result of the impurity and is given by

$$ H_1 = |\ell > \varepsilon < \ell | $$

((6.3))

.