Abstract
We present resonant x-ray Raman scattering results on Sr2CuO2Cl2, a model compound for high-T-c superconductors. We demonstrate that the dd excitations can be observed and show that the polarization dependence can be used to identify the dd excitations. We find the transition from the d(x2-y2) ground state to the d(xy) excited state at 1.35 eV and to the degenerate d(xz) and d(yz) excited states at 1.7 eV. From analysis of the polarization dependence we conclude that the d(3z2-r2) orbital energy is at 1.5 eV and not in the midinfrared (0.5 eV) as recently suggested. We use recent theoretical arguments to show that the d(3z2-r2) excitation is accompanied by a local spin flip resulting in a shift upwards of 0.2 eV due to the exchange interaction with the neighboring spins.
Original language | English |
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Pages (from-to) | 5204-5207 |
Number of pages | 4 |
Journal | Physical Review Letters |
Volume | 80 |
Issue number | 23 |
Publication status | Published - 8 Jun 1998 |
Externally published | Yes |
Keywords
- LAMELLAR COPPER OXIDES
- FLUORESCENCE SPECTROSCOPY
- OPTICAL-ABSORPTION
- EMISSION SPECTRA
- LA2CUO4