Effects of Disorder on Charge Orderings and Superconductivity in the System of Coexisting Itinerant Electrons and Local Pairs

We study the phase diagrams and thermodynamic properties of a system of coexisting itinerant electrons and local pairs (LP), in the presence of diagonal disorder. The model considered takes into account both the charge exchange couplings, responsible for superconducting orderings, and the density-density interactions, which can stabilize charge ordered states in the system. Depending on the strength of the random on-site potential, the interactions and the particle concentrations the model is found to exhibit several various phases, including the homogeneous ones: superconducting (SC), charge density wave (CDW) and nonordered (NO), as well as the phase separated states (CDW-SC and CDW-NO).