Optical properties of the Ce and La ditelluride charge density wave compounds

M. Lavagnini, A. Sacchetti, L. Degiorgi, K. Y. Shin, I. R. Fisher
2007 Physical Review B  
The La and Ce di-tellurides LaTe_2 and CeTe_2 are deep in the charge-density-wave (CDW) ground state even at 300 K. We have collected their electrodynamic response over a broad spectral range from the far infrared up to the ultraviolet. We establish the energy scale of the single particle excitation across the CDW gap. Moreover, we find that the CDW collective state gaps a very large portion of the Fermi surface. Similarly to the related rare earth tri-tellurides, we envisage that interactions
more » ... nd Umklapp processes play a role in the onset of the CDW broken symmetry ground state.
doi:10.1103/physrevb.75.205133 fatcat:y6frbj7pjzhv3nlyq2h5qf57q4