Momentum-resolved electronic excitations in the Mott insulator SrIrO studied by resonant inelastic X-ray scattering

共鳴非弾性X線散乱による新奇なモット絶縁体SrIrOの運動量分解した電子励起の研究

石井 賢司; Jarrige, I.; 吉田 雅洋; 池内 和彦*; 水木 純一郎; 大橋 啓*; 高山 知弘*; 松野 丈夫*; 高木 英典*

Ishii, Kenji; Jarrige, I.; Yoshida, Masahiro; Ikeuchi, Kazuhiko*; Mizuki, Junichiro; Ohashi, Kei*; Takayama, Tomohiro*; Matsuno, Jobu*; Takagi, Hidenori*

We report an Ir -edge resonant inelastic X-ray scattering (RIXS) measurement of the low-lying electronic excitations in SrIrO over the complete Brillouin zone of the IrO plane. A remarkably strong inelastic signal which exceeds the elastic scattering in intensity is observed. Peaks observed at 0.5, 3.2, and 6.0 eV are respectively ascribed to an interband transition across the Mott gap and charge-transfer excitations from the O band to the Ir bands. The dispersion of the Mott gap excitation is found to be particularly weak. This is interpreted as a signature of the narrow bands of the novel Mott insulating state of SrIrO induced by the strong spin-orbit interaction.