Electronic Structure of the Heavy Fermion MetalLiV2O4

The electronic structure of the first reported heavy fermion compound without $f$ electrons, ${\mathrm{LiV}}_2{\mathrm{O}}_4$, was studied by an ab initio calculation method. As a result of the trigonal splitting and $d-d$ Coulomb interaction, one electron of the $d^{1.5}$ configuration of the V ion is localized and the rest partially fills a relatively broad conduction band. The effective Anderson impurity model was solved by the non-crossing-approximation method, leading to an estimation for the single-site Kondo energy scale $T_K$. Then, we show how the so-called exhaustion phenomenon of Nozières for the Kondo lattice leads to a remarkable decrease of the heavy-fermion (or coherence) energy scale $T_{\mathrm{coh}}\equiv T_K^2/D$ ( $D$ is the typical bandwidth), comparable to the experimental result.