Onset of Superconductivity: Domain Wall Instability vs. Topological Explosion

Recovery of superconductivity in the previously heated and being cooled sample is studied by the direct solution of the time-dependent Ginzburg-Landau (TDGL) equations coupled with the heat transfer equations. Two competing mechanisms of superconducting nucleation are found. It is shown that in the fast cooling regime the explosive topological instability develops across the entire previously heated area, while in the opposite case azimuthal instability of the boundary wall between heated and superconducting regions leads to detachment of closed Abrikosov vortex (AV) chain.