Ab initio study on heavy-fermion behavior in LiV₂O₄: Role of Hund's coupling and stability

LiV₂O₄ is a member of the so-called 3d heavy fermion compounds, with effective electron mass exceeding 60 times the free electron mass, comparable to 4f heavy fermion compounds. The origin of the strong electron correlation in combination with its metallic character have been a subject of intense theoretical and experimental discussion, with Kondo-like physics and Mott-physics being suggested as its physical origin. Here we report state-of-the art ab initio Density Functional Theory + dynamical mean-field theory calculations for LiV₂O₄ for the full three orbital V t_2g manifold, and present temperature-dependent spectral properties. We map out the phase diagram for a representative 3-orbital model system as a function of doping and interaction strength, which indicates that LiV₂O₄ is located between two orbital-selective Mott phases, giving rise to a robust strongly correlated Hund's metal behavior. At low temperature we find the emergence of a strongly renormalized sharp quasi-particle peak a few meV above the Fermi level of V a_1g character, in agreement with experimental reports.