Abstract
The La and Ce ditellurides and are deep in the charge-density-wave (CDW) ground state even at . 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 large portion of the Fermi surface. Based on the observation of a power-law behavior in the optical conductivity, similar to that found for the related rare-earth tritellurides but over a reduced frequency range, we suggest that interactions and umklapp processes may play a role in the onset of the CDW broken-symmetry ground state.
- Received 19 January 2007
DOI:https://doi.org/10.1103/PhysRevB.75.205133
©2007 American Physical Society