Quasi-one-dimensional superconductors in strong magnetic field.
We determine the phase diagram of a quasi-one-dimensional superconductor (weakly coupled chains system with an [ital open] [ital Fermi] [ital surface]) in a magnetic field. The usual Ginzburg-Landau regime is followed, when the field is increased, by a [ital cascade] of superconducting phases separated by first-order transitions, which ends in a strong reentrance of the superconducting phase. These new phases show a novel kind of symmetry of a laminar type. The Zeeman splitting does not completely suppress the reentrance in very strong field, the ground state being in this case a Larkin-Ovchinnikov-Fulde-Ferrell state.