Phase coexistence in a half-filled extended Hubbard model

In this Letter we analyze the coexisting ordered phases that arise in the half-filled $\varepsilon$-t-U-V extended Hubbard Model on the square lattice when tackled within the Kotliar andRuckenstein slave boson representation in the thermodynamical limit. Particular emphasis is put on the dependence of the quasiparticle dispersions, the gaps, the spin-resolved renormalization factors, and the distribution of double occupancy on the microscopical parameters of the model. Our calculations are performed in a parameter range that is most suitable for resistive switching. In particular, the main contributions to the gaps are shown to either arise from $\varepsilon$ in the weak coupling regime, or from U and V when they are the largest scales. The gaps are thus from joint spin and charge origin, and so are the order parameters.