VELOCITY SELECTION FOR PROPAGATING FRONTS IN SUPERCONDUCTORS

Using the time-dependent Ginzburg-Landau equations we study the propag ation of planar fronts in superconductors, which would appear after a quench to zero applied magnetic field. Our numerical solutions show th at the fronts propagate at a unique speed which is controlled by the a mount of magnetic flux trapped in the front. For small flux the speed can be determined from the linear marginal stability hypothesis, while for large flux the speed may be calculated using matched asymptotic e xpansions. At a special point the order parameter and vector potential are dual, leading to an exact solution which is used as the starting point for a perturbative analysis.