Raman Scattering from Semiconducting and Metallic Ge(As)

Abstract

By use of an yttrium aluminum garnet laser operating at 2.1 \ensuremath{\mu}m, polarized transmission Raman spectra of Ge(As) have been measured for impurity concentrations spanning the Mott transition. The valley-orbit Raman line broadens markedly at the transition; its line shape has been fitted using the London-Heitler method. The spectrum in the metallic regime constitutes the first observation of single-particle scattering from intervalley fluctuations.