Flux dynamics and the growth of the superconducting phase

We present a detailed investigation of the growth of the superconducting phase in a magnetic field. For type-I superconductors, the planar normal-superconductor interface is dynamically unstable. In the nucleation regime this feature leads to interface motion similar to that found in the solid-liquid transition. In the spinodal regime the spinodal growth proceeds by a sequence of phase-slip processes, unique to a system with a complex order parameter. In type-II superconductors, vortex absorption stabilizes a planar interface, despite the negative surface tension.