Optical Process of Linear Dichroism in Angle-Resolved Core-Level   Photoemission Reflecting Strongly Correlated Anisotropic Orbital Symmetry
  We revisit the formulations and simulations of angular distributions in polarization-dependent core-level photoemission spectra of strongly correlated electron systems, in order to explain the recently discovered linear dichroism (LD) in the core-level photoemission of 4f-based rare-earth compounds. Owing to the selection rules for the optical process of core-level excitations, the LD originating from the anisotropic outer localized charge distributions determined by the ground-state orbital symmetry can be observed. Our simulations show that core d-level excitations are essential for the LD in localized ions having a cubic symmetry, which is absent in the p-orbital excitations. 
Akira Sekiyama, Yuina Kanai, Arata Tanaka, and Shin Imada
cond-mat.str-el cond-mat.mtrl-sci