Ground state phase diagram of the repulsive SU(3) Hubbard model in Gutzwiller approximation

TL;DR

This study uses a variational Gutzwiller approach to map out the ground state phases of the repulsive SU(3) Hubbard model on a Bethe lattice, revealing five distinct phases and their transitions.

Contribution

It provides the first detailed phase diagram for the SU(3) Hubbard model with a focus on two-sublattice structures and phase transitions, highlighting differences from the SU(2) case.

Findings

Identified five relevant phases including paramagnet, ferromagnet, and various antiferromagnetic states.

Discovered first-order phase transitions leading to phase separation.

Showed that doping effects differ significantly between SU(3) and SU(2) models.

Abstract

We perform a variational Gutzwiller calculation to study the ground state of the repulsive SU(3) Hubbard model on the Bethe lattice with infinite coordination number. We construct a ground-state phase diagram focusing on phases with a two-sublattice structure and find five relevant phases: (1) a paramagnet, (2) a completely polarized ferromagnet, (3) a two-component antiferromagnet where the third component is depleted, (4) a two-component antiferromagnet with a metallic third component (an "orbital selective" Mott insulator), and (5) a density-wave state where two components occupy dominantly one sublattice and the last component the other one. First-order transitions between these phases lead to phase separation. A comparison of the SU(3) Hubbard model to the better-known SU(2) model shows that the effects of doping are completely different in the two cases.