Sm 4f electronic state of heavy fermion compound SmOs₄Sb ₁₂ by theory of high-energy spectroscopy

We calculate a set of high-energy spectra, such as the Sm 3d X-ray absorption spectrum and X-ray photoemission spectrum using a configuration-interaction full-multiplet theory to investigate the Sm 4f electronic state of SmOs₄Sb₁₂. In the study of SmOs ₄Sb₁₂ performed so far, the ground state was expressed by a linear combination of the f⁵ electron configuration and its charge transfer (CT) states, which indicates that the local symmetry is J = 5/2. In contrast, the present study shows that the ground state expressed by the f ⁶ electron configuration and its CT states can also reproduce the experiments well. We note that the f⁶-based ground state, the local symmetry of which is J = 0, is of great advantage for discussing the experimental result that the heavy fermion state of SmOs₄Sb ₁₂ is insensitive to the applied magnetic field. We predict that the f⁶-based ground state will be justified by the Sm 3d X-ray magnetic circular dichroism.