1T-TiTe2: scattering rate from infrared and Raman data

The normal-state properties of high temperature superconductors (HTSC) are usually described as those of a non-Fermi liquid, on account of the unusual temperature and frequency dependence of their optical and dc conductivities. This description can be challenged, however, because one has no good example Fermi-liquid (FL) behavior for comparison, especially considering the quasi two-dimensionality of the HTSC. One could address this issue with the help of a reference compound 1T-TiTe$_{2.}$ Both transport and photoemission data on 1T-TaTe$_{2}$ agree well with the Fermi liquid predictions. Thus 1T-TaTe$_{2}$ is believed to be a ``model Fermi liquid''. However, the key signature of the FL is the frequency and temperature dependence of the carrier scattering rate. In this report we discuss our infrared and Raman measurements of the scattering rate in 1T-TiTe$_{2}$ and compare our date to the available photoemission and transport data. $^{\ast }$Supported by Petroleum Research Fund award {\#} 40926-GB10 and Research Corporation Cottrell College science award {\#} cc6130