Observation of optical phonons bound to neutral donors

Abstract

We have observed new "local-mode lattice vibrations" in GaP, both in Raman scattering and as cooperating phonons in optical transitions. The modes are best qualitatively described as a particle-the LO phonon -bound to a neutral donor, which provides an effective attractive interaction for the phonon. In this analogy, bound states having various angular momenta around the donor can be expected, and both S and P states have been identified experimentally. © 1970 The American Physical Society.