Time-Dependent Gutzwiller Theory for Multiband Hubbard Models

Based on the variational Gutzwiller theory, we present a method for the computation of response functions for multiband Hubbard models with general local Coulomb interactions. The improvement over the conventional random-phase approximation is exemplified for an infinite-dimensional two-band Hubbard model where the incorporation of the local multiplet-structure leads to a much larger sensitivity of ferromagnetism on the Hund coupling. Our method can be implemented into LDA+Gutzwiller schemes and will therefore be an important tool for the computation of response functions for strongly correlated materials.Comment: 4 pages, 3 figure

Valence bond dynamical mean-field theory of doped Mott insulators with nodal/antinodal differentiation

We introduce a valence bond dynamical mean-field theory of doped Mott insulators. It is based on a minimal cluster of two orbitals, each associated with a different region of momentum space and hybridized to a self-consistent bath. The low-doping regime is characterized by singlet formation and the suppression of quasiparticles in the antinodal regions, leading to the formation of Fermi arcs. This is described in terms of an orbital-selective transition in reciprocal space. The calculated tunneling and photoemission spectra are consistent with the phenomenology of the normal state of cuprates. We derive a low-energy description of these effects using a generalization of the slave-boson method