Self-organization of vortices in type-II superconductors during magnetic relaxation

We revise applicability of the theory of self-organized criticality ͑SOC͒ to the process of magnetic relaxation in type-II superconductors. The driving parameter of self-organization of vortices is the energy barrier for flux creep and not the current density. The power spectrum of the magnetic noise due to vortex avalanches is calculated and is predicted to vary with time during relaxation. ͓S0163-1829͑99͒07221-5