The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4

We calculate the electronic structure of Sr2RuO4, treating correlations in the framework of dynamical mean-field theory. The approach successfully reproduces several experimental results and explains the key properties of this material: the anisotropic mass renormalization of quasiparticles and the crossover into an incoherent regime at a low temperature. While the orbital differentiation originates from the proximity of the van Hove singularity, strong correlations are caused by the Hund's coupling. The generality of this mechanism for other correlated materials is pointed out.