Multiple insulating phases due to the interplay of strong correlations and lattice geometry in a single-orbital Hubbard model

Abstract

We find ten distinct ground states for the single-orbital Hubbard model on the decorated honeycomb lattice, which interpolates between the honeycomb and kagome lattices, and is the simplest two-dimensional net. The rich phase diagram includes a real-space Mott insulator, dimer and trimer Mott insulators, a spin triplet Mott insulator, flat band ferromagnets, and Dirac metals. It is determined as a function of interaction strength, band filling, and hopping anisotropy, using rotationally invariant slave boson mean-field theory.

Unconventional superconductivity near a flat band in organic and organometallic materials

“…2 (inset)]. This leads to large density of states so one expects strong electronic correlation effects close to half-filling [14]. The DHL is realized in several materials including trinuclear organometallic compounds [15][16][17][18][19], organic molecular crystals [20], iron(III) acetates [21], coordination polymers/metal-organic frameworks (MOFs) [22,23], and cold fermionic atoms in optical lattices [24].…”