Superconductivity, charge orderings, magnetism, and their phase separations in the ground state of lattice models of superconductor with very short coherence length

Abstract

We present the ground state results for lattice models of superconductor (SC) with extremely short coherence length, which also involve the interplay with charge (CO) and (anti-)ferromagnetic orderings. Our preliminary results at zero-temperature (derived by means of the variational approach which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation, exact in $d\rightarrow+\infty$), yields that the SC phase can coexist with the CO or magnetic (M) phases in states with electron phase separation (PS:SC/CO and PS:SC/M, respectively).