The first-order vortex transition line in three-dimensional anisotropic superconductors in tilted magnetic fields

The vortex lattice in high-temperature superconductors is affected by thermal fluctuations and quenched disorder, leading to disordered phases, such as vortex liquid and glass, through a first-order phase transition. We use a transformation proposed by Calero, in order to obtain the angular generalization of the first-order melting line of the vortex lattice in a three-dimensional anisotropic superconductor, such as YBaCuO, under an external magnetic field with arbitrary direction with respect to the anisotropy axis. The calculations are performed in the framework of the Ginzburg-Landau theory in the lowest Landau level approximation. The competition between thermal fluctuations and disorder is described following the same method as that developed by Li and Rosenstein.