Local-Field Correction for an Interstitial Impurity in Crystal
A Rahmani, P C. Chaumet, G C. Bryant
The local-field correction experienced by an interstitial impurity in a crystal with cubic symmetry is derived by use of a rigorous, self-sonsistent, semi-microscopic description of spontaneous emission in a microcavity. We compute the local-field factor for various positions of the impurity inside the crystal. Furthermore, we demonstrate that the local-field factor can be computed from a simple model as a rapidly converging lattice sum. We show that the agreement between the predictions of this simple model and the rigorous calculations is remarkable, opening the way to a simple, general theory of local-field effect for an impurity in a crystal with arbitrary symmetry.