Dielectric function in HgTe between 8 and 300°K

摘要: Reflectivity spectra of HgTe were measured in the spectral region from 80 to 600 ${\mathrm{cm}}^{\ensuremath{-}1}$ at temperatures between 8 and 300\ifmmode^\circ\else\textdegree\fi{}K. The wave numbers transverse-optical phonon ${\ensuremath{\omega}}_{\mathrm{TO}}=117$ longitudinal-optical ${\ensuremath{\omega}}_{\mathrm{LO}}=132$ 8\ifmmode^\circ\else\textdegree\fi{}K determined. total dielectric function including interband ${\ensuremath{\Gamma}}_{8}\ensuremath{-}{\ensuremath{\Gamma}}_{8}$ contribution was analyzed. Plasmon-phonon dispersion diagrams obtained. theoretical analysis is compared with experimental results all temperatures. Possible consequences adiabatic approximation breaking down zero-gap semiconductors examined. A new low-frequency mode reported, its temperature dependence given, origin discussed physicochemical arguments.