We report resonant inelastic x-ray scattering experiments of the orbitally ordered manganite (formula presented) When incident photon energy is tuned near the Mn K absorption edge, the spectra reveal three features at 2.5, 8, and 11 eV. The 8- and 11-eV peaks are ascribed to transitions from the O (formula presented) bands to the empty Mn (formula presented) and (formula presented) bands, respectively. On the other hand, the 2.5-eV peak is considered an orbital excitation across the Mott gap, i.e., an electron excitation from the effective lower Hubbard band with the (formula presented) and (formula presented) orbital characters to the upper Hubbard band with the (formula presented) and (formula presented) ones. The weak dispersion and characteristic azimuthal angle dependence of this excitation are well reproduced by a theory which includes orbital degeneracy and strong electron correlation.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2003 1月 27|
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