The phase diagram and inhomogenous superconductivity in the one-dimensional attractive Hubbard model

The thermodynamic phase diagram of the attractive Hubbard model in the presence of magnetic field is calculated in wide range of temperature, electron concentration and coupling strength within the generalized self-consistent field (GSCF) approach, including the spin density correlations. The theory provides a smooth transition driven by applied magnetic field h and temperature T from the homogoneous superconducting state into a spatially inhomogeneous state with the order parameter Δ Q (−) ≠ 0.