Kapcia, Konrad2013-09-022013-09-022013-08Journal of Superconductivity and Novel Magnetism, Vol. 26, No. 8, 2647-2650 (2013)1557-1939http://link.springer.com/article/10.1007/s10948-013-2152-1http://hdl.handle.net/10593/7705This is an author-created, un-copyedited version of an article accepted for publication in Journal of Superconductivity and Novel Magnetism.We present studies of an effective model which is a simple generalization of the standard model of a local pair superconductor with on-site pairing (i.e., the model of hard core bosons on a lattice) to the case of finite pair binding energy. The tight binding Hamiltonian consists of (i) the effective on-site interaction U, (ii) the intersite density-density interactions W between nearest-neighbours, and (iii) the intersite charge exchange term I, determining the hopping of electron pairs between nearest-neighbour sites. In the analysis of the phase diagrams and thermodynamic properties of this model we treat the intersite interactions within the mean-field approximation. Our investigations of the U<0 and W>0 case show that, depending on the values of interaction parameters, the system can exhibit three homogeneous phases: superconducting (SS), charge-ordered (CO) and nonordered (NO) as well as the phase separated SS-CO state.ensuperconductivitycharge orderingsextended Hubbard modelatomic limitphase separationlocal pairingArtykułhttps://doi.org/10.1007/s10948-013-2152-1