Optical study of the electronic phase transition of strongly correlated
- Author(s): Garner, SR
- Hancock, JN
- Rodriguez, YW
- Schlesinger, Z
- Bucher, B
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevB.62.R4778
Infrared, visible, and near-UV reflectivity measurements are used to obtain conductivity as a function of temperature and frequency in (Formula presented) which exhibits an isostructural phase-transition into a mixed-valent phase below (Formula presented) In addition to a gradual loss of spectral weight with decreasing temperature extending up to 1.5 eV, a sharp resonance appears at 0.25 eV in the mixed-valent phase. This feature can be described in terms of excitations into the Kondo (Abrikosov-Suhl) resonance, and, like the sudden reduction of resistivity, provides a direct reflection of the onset of coherence in this strongly correlated electron system. © 2000 The American Physical Society.