Time-Dependent Gutzwiller Theory for Multiband Hubbard Models

TL;DR

This paper introduces a Gutzwiller-based method to compute response functions in multiband Hubbard models, capturing local multiplet effects and improving upon traditional approximations, with applications to strongly correlated materials.

Contribution

The paper develops a novel variational Gutzwiller approach for response functions in multiband Hubbard models, incorporating local multiplet structures.

Findings

Enhanced sensitivity of ferromagnetism to Hund coupling in the model

Method can be integrated into LDA+Gutzwiller schemes

Improves accuracy over random-phase approximation

Abstract

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.