Charge dynamics in YVO investigated by resonant inelastic X-ray scattering

Ikeuchi, Kazuhiko; Jarrige, I.; Ishii, Kenji; Inami, Toshiya; Mizuki, Junichiro; Bizen, Daisuke*; Murakami, Yoichi*; Miyasaka, Shigeki*; Fujioka, Jun*; Tokura, Yoshinori*

YVO is a transition metal perovskite archetypal of Mott insulators with partially occupied orbitals. Intricate interactions between charge, spin, orbital and lattice result in two kinds of characteristic spin and orbital order that can be switched from one to the other with changing temperature across = 75 K. We studied the effect of spin and orbital ordering patterns on the charge excitations in YVO using resonant inelastic X-ray scattering at the V K-edge (5.483 keV). Two peaks have been systematically observed around 2 and 2.7 eV, identified as the Mott gap excitations. The on-set energy of the 2 eV peak is estimated to be 1.5 eV in good agreement with a previous estimation of the Mott-Hubbard gap by optical conductivity. The temperature, momentum and polarization dependences of the data allow first-hand insight into the anisotropic behavior of the Mott gap excitations.