Peculiar temperature-dependent charge response of frustrated chain cuprates near a critical point
Abstract
The optical conductivity σ(ω) is calculated at finite temperature T for CuO2 chain clusters within a pd-Hubbard model. Data at T = 300 K for Li2CuO2 are reanalyzed within this approach. The relative weights of Zhang-Rice singlet and triplet charge excitations near 2.5 and 4 eV, respectively, depend strongly on T, and a dramatic dependence of σ(ω) on the ratio of the 1st to 2nd neighbor exchange integrals is predicted. Information about exchange interactions for edge-shared cuprates can be obtained from T-dependent optical spectra. A reduced intensity of the ZRS-transition with increasing T is also relevant for unfrustrated cuprates in general.
- Publication:
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Journal of Physics Conference Series
- Pub Date:
- January 2009
- DOI:
- 10.1088/1742-6596/145/1/012060
- Bibcode:
- 2009JPhCS.145a2060D