Ginzburg-Landau functional for type-II superconductors with Pauli paramagnetic effect

Effects of Pauli paramagnetism on type-II superconductivity are examined through a derivation of a Ginzburg-Landau (GL) functional by including the field-induced pair-breaking effects through the spin and orbital on an equal footing. On the basis of the resultant GL functional we discuss the corresponding high-field vortex phase diagram at the level of mean field approximation. Special attention is paid to the mutuality of characteristic temperatures, i.e., the temperatures: (1) at which the vortex state is described in terms of higher Landau levels; (2) at which a vortex state modulated along the field direction (a Fulde-Ferrell-Larkin-Ovchinnikov-like state) becomes stable; and (3) at which a superconducting transition becomes nearly discontinuous.