PHASE-DIAGRAM OF THE FULDE-FERRELL-LARKIN-OVCHINNIKOV STATE IN A 3-DIMENSIONAL SUPERCONDUCTOR

The phase diagram of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a 5-dimensional superconductor is discussed. We use the quasi-clas sical Green's function to calculate the free energy. It is shown that the phase transition from the normal state is of first order at high t emperatures but is of second order near T = 0. To describe the phase t ransition in the Ginzburg-Landau theory; one has to take into account up to eighth order term with respect to the order parameter. The phase transition from the FFLO state to the uniform superconducting state i s of second order in all the temperature range T < 0.561T(c) in accord ance with Burkhardt and Rainer's result in a 2-dimensional system.