Nonresonant inelastic x-ray scattering and energy-resolved Wannier function investigation of d-d excitations in NiO and CoO

作者:Larson B C*; Ku Wei; Tischler J Z; Lee Chi Cheng; Restrepo O D; Eguiluz A G; Zschack P; Finkelstein K D
来源:Physical Review Letters, 2007, 99(2): 026401.
DOI:10.1103/PhysRevLett.99.026401

摘要

Nonresonant inelastic x-ray scattering measurements on NiO and CoO show that strong dipole-forbidden d-d excitations appear within the Mott gap at large wave vectors. These dominant excitations are highly anisotropic, and have [001] nodal directions for NiO. Theoretical analyses based on a novel, energy-resolved Wannier within the local density approximation + Hubbard U) show that the anisotropy reflects the local exciton wave functions and local point-group symmetry. The sensitivity to weak symmetry breaking in particle-hole wave functions suggests a wide application to strongly correlated systems.

  • 出版日期2007-7-13