Phase diagram of vortex matter of type-II superconductors

Abstract

We propose a model to construct the phase diagram for type-II superconductors through molecular-dynamics simulation. In this model, the Abrikosov vortices interact with long-range repulsion and short-range attraction. We are able to obtain the phase diagrams consisting of the vortex lattice, the intermediate-mixed phase (IMP), and the disordered vortex phase in the $B$-$T$, $B$-$\ensuremath{\kappa}$, and $B$-$q$ planes, where $B$ is induction, $\ensuremath{\kappa}$ is the Ginzburg-Landau parameter, and $q$ is the relative strength of the attraction to repulsion interactions between vortices. The IMP is in the form of a superlattice of either vortex bubbles or parallel vortex stripes, agreeing excellently with experimental results that have not yet been explained by existing models.