Electronic structure of CeCoSi using first principle band calculation

Yasui, Akira; Yamagami, Hiroshi

We have obtained the electronic structure of CeCoSi, which is typical compounds in the heavy-fermion system, using a first-principle band calculation with the relativistic linearized-augmented-plane-wave method. I compared calculated results with the band dispersion and the Fermi surface (FS) formation obtained by the Ce 3-4 resonant angle-resolved photoemission spectra at BL23SU of SPring-8. As the result, the calculated FS formation is good agreement with experimental one. The LDA calculation explains the experimental band dispersion roughly. However there are some problems: especially, the valence band obtained by the experiment shows the energy shift to higher side compared with one by LDA calculation. This problem is due to the strong electronic correlation. Ce 4 band which pushes down the valence band shifts to higher energy because of the strong electron-electron interaction.