Orbital excitations in LaMnO3 studied by resonant inelastic x-ray scattering

作     者：T. Inami T. Fukuda J. Mizuki S. Ishihara H. Kondo H. Nakao T. Matsumura K. Hirota Y. Murakami S. Maekawa Y. Endoh 

作者机构：Core Research for Evolutional Science and Technology (CREST) Tsukuba 305-0047 Japan 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2003年第67卷第4期

页      面：045108-045108页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

摘      要：We report resonant inelastic x-ray scattering experiments of the orbitally ordered manganite LaMnO3. 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 2p bands to the empty Mn 3d and 4s/4p 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 d3x2−r2 and d3y2−r2 orbital characters to the upper Hubbard band with the dy2−z2 and dz2−x2 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.