QUASI-ONE-DIMENSIONAL SUPERCONDUCTORS IN STRONG MAGNETIC-FIELD

We determine the phase diagram of a quasi-one-dimensional conductor (weakly coupled chains system with an open Fermi surface) in a magnetic field. The superconducting state evolves from an Abrikosov vortex lattice in weak field to a Josephson vortex lattice in very strong field, with a reentrance of the superconducting phase. Between these two limits, there is a cascade of first order transitions between different superconducting phases due to commensurability effects between the crystalline lattice and the order parameter. In these phases, the order parameter has a laminar structure.