Evidence of Coupling Between One- and Two-Phonon Excitations in Quartz

作者：James Floyd Scott · 发表于：Physical Review Letters · 年份：1968 · DOI：10.1103/physrevlett.21.907 · 被引用次数：131 · 研究领域：Solid-state spectroscopy and crystallography、Spectroscopy and Quantum Chemical Studies、Quantum, superfluid, helium dynamics

We have extended earlier work on the Raman spectrum of quartz to both higher and lower temperatures (6-900\ifmmode^\circ\else\textdegree\fi{}K), and find evidence for the assignment of features in the 130- to ${200\ensuremath{-}\mathrm{c}\mathrm{m}}^{\ensuremath{-}1}$ region as second order. Anomalies in the temperature dependence and selection rules exhibited by several features are fully reconciled by an anharmonic interaction between a "soft" zone-center optical phonon and an excitation consisting of two oppositely directed zone-edge acoustic phonons.