The reflectivity spectra of La2-xSrxCuO4 for x=0 and 0.175, and Ba2YCucO9- (2.1) were measured over a broad frequency range, from 0.005 to 3 eV. In the normal state of these compounds the reflectivity is temperature independent and significantly smaller than expected from the Drude model. We describe a dielectric function which reproduces the main features of the spectra by supplementing the Drude contribution with a strong transition across a gap.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics