Impact of Rashba spin-orbit coupling on f-electron materials

We study the interplay between Rashba spin-orbit coupling (RSOC) and the Kondo screening in noncentrosymmetric f-electron materials. We show that the Kondo interaction of the f-electrons becomes anisotropic at high temperatures due to the RSOC in these materials leading to a suppression of the Kondo temperature. However, an isotropic Kondo effect is restored at low temperature which leads to a complete Kondo screening. We furthermore demonstrate that the Kondo effect has influence on the Rashba splitting in the band structure, which becomes temperature dependent. We show that although f electrons are localized at temperatures above the Kondo temperature, already at these temperatures a helical spin polarization emerges. With decreasing temperature, the Kondo screening occurs, which leads to drastic changes in the band structure. Remarkably, these changes in the band structure depend on the helical spin polarization. For strong RSOC, we observe that one of the helical bands becomes gapped at low temperature and a helical half-metal is formed.