Spin-orbit interaction and quasiparticle bands in locally non-centrosymmetric heavy-fermion systems*

Non-centrosymmetric heavy-fermion systems (HFS) have gained much interest in the past decade. In these materials, the lack of inversion symmetry in combination with strong spin-orbit interaction and magnetic interactions can lead to novel phenomena. In this talk, we present calculations of the heavy quasiparticle bands in Ce- and Yb-based HFS from the tetragonal 122-family. This class of materials comprises compounds with the inversion-symmetric ThCr2Si2 structure as well as systems with the locally non-centrosymmetric CaBe2Ge2 structure. The calculations are performed by means of the Renormalized Band method which proceeds from a Dirac.relativistic description of the electronic structure and accounts for Crystalline Electric Field effects and the mass renormalization due to strong local correlations. We discuss results for YbIr2Si2 which crystallizes in both structures depending on preparation condition. Further on, we present results on the new HFS CeRh2As2.