Auger-Like Resonant Interference in Raman Scattering from One- and Two-Phonon States of BaTiO3

Resonant interference between one- and two-phonon states has been observed in BaTi${\mathrm{O}}_3$, and has been shown to obey the quantum mechanical formalism developed by Fano for Auger processes. By selecting different components of the differential polarizability tensor and by changing the propagation direction, the degree of interference could be varied over a wide range. The linewidth and line-profile parameters were determined for several different crystal orientations.