Vortex Phase Diagram for Mesoscopic Superconducting Disks

Solving numerically the 3D nonlinear Ginzburg-Landau (GL) equations, we study equilibrium and nonequilibrium phase transitions between different superconducting states of mesoscopic disks which are thinner than the coherence length and the penetration depth. We have found a smooth transition from a multivortex superconducting state to a giant vortex state by increasing both the disk thickness and the magnetic field. A vortex phase diagram is obtained which shows, as a function of the magnetic field, a reentrant behavior between the multivortex and the giant vortex state.