SPring-8, the large synchrotron radiation facility

Date & Time: 5 November 2004, 14:00-15:00

Speaker: Prof. Junichi Igarashi
Affiliation: Ibaraki University

Abstract
　　We report a recent activity of our group on the theoretical analysis of resonant x-ray scattering (RXS) spectra.
　　First, we present the analysis of Cr K-edge resonant magnetic scattering spectra in the spin density wave (SDW) state. We perform the band structure calculation assuming a commensurate SDW state with the propagation vector close to the observed value. We obtain the RXS spectra in good agreement with the experiment. In spite of the tiny orbital moment, the orbital polarization is found to have large fluctuations as a function of energy. This causes a large orbital polarizartion in the 4p band through the p-d hybridization, thereby a large RXS intensity is brought about.
　　Second, we present the analysis of U M-edge RXS spectra in URu₂Si₂.
　　Our analysis is based on a localized crystal electric field model for U⁴⁺ in the 5f²-configuration with full Coulomb and spin-orbit interactions taken into account. We calculate the RXS spectran assuming the dipole, quadrupole and octupole orders, in comparison with the experiment.