Electron and Orbital Correlations in Ca2-xSrxRuO4 Probed by Optical Spectroscopy
Abstract
The optical conductivity spectra of the quasi-two-dimensional Ca2-xSrxRuO4 (0.0<=x<=2.0) system were investigated. In the Mott insulating state, two electron correlation-induced peaks were observed about 1.0 and 1.9eV, which could be explained using the 3-orbital Hubbard model. The low frequency peak showed a shift toward higher frequency as temperature was lowered, indicating that electron-phonon interactions play an important role in the orbital arrangements. From the systematic analysis, it was suggested that the antiferro-orbital and the ferro-orbital ordering states could coexist.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2002
- DOI:
- 10.1103/PhysRevLett.89.257402
- arXiv:
- arXiv:cond-mat/0208075
- Bibcode:
- 2002PhRvL..89y7402L
- Keywords:
-
- 78.20.Ci;
- 71.27.+a;
- 71.30.+h;
- 78.30.-j;
- Optical constants;
- Strongly correlated electron systems;
- heavy fermions;
- Metal-insulator transitions and other electronic transitions;
- Infrared and Raman spectra;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 12 pages, 4 figures