Abstract
Optical conductivity data of the intermetallic compounds ( ) reveal that their density of states around the Fermi energy ( ) is strongly reduced as is increased. In particular, ( ) has a deep, well-developed pseudogap of at and a small density ( ) of carriers, which is highly unusual for intermetallic compounds. It is shown that the pseudogap results from the band structure of , rather than from temperature-dependent correlation effects. Based on the present results, we propose a simple model that consistently explains both the semiconductorlike transport and the metallic photoemission results previously observed for .
- Received 19 October 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.3674
©2000 American Physical Society