Enhanced Spin Orbit Interaction in Actinides

Abstract

Abstract We investigate the effect of many-body interactions on the spin-orbit coupling of anisotropic metals. We use the Underscreened Anderson Lattice Model that was proposed to describe actinide compounds. The Coulomb interactions induce off-diagonal correlations that enhance the components of the spin-orbit coupling. Modest values of the Coulomb interaction U can significantly enhance the spin-orbit coupling and effect the electronic spectrum. The enhancements are most pronounced for systems that are on the verge of magnetic instabilities. The enhancement is anisotropic in crystals with non-cubic symmetries and can lead to giant magnetic anisotropies in paramagnetic states.