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Resonant inelastic x-ray scattering study of charge excitations in La2CuO4

Y. J. Kim·J. P. Hill·C. A. Burns·S. Wakimoto·R. J. Birgeneau·D. Casa·T. Gog·C. T. Venkataraman
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Abstract

We report a resonant inelastic x-ray scattering study of the dispersion relations of charge transfer excitations in insulating La$_2$CuO$_4$. These data reveal two peaks, both of which show two-dimensional characteristics. The lowest energy excitation has a gap energy of $\sim 2.2$ eV at the zone center, and a dispersion of $\sim 1$ eV. The spectral weight of this mode becomes dramatically smaller around ($π$, $π$). The second peak shows a smaller dispersion ($\sim 0.5$ eV) with a zone-center energy of $\sim 3.9$ eV. We argue that these are both highly dispersive exciton modes damped by the presence of the electron-hole continuum.

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Y. J. Kim, J. P. Hill, C. A. Burns, S. Wakimoto, R. J. Birgeneau, D. Casa, T. Gog, C. T. Venkataraman. 2002-06-27. Resonant inelastic x-ray scattering study of charge excitations in La2CuO4. https://doi.org/10.1103/physrevlett.89.177003

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