Flux creep in Bi₂Sr₂CaCu₂O₈ epitaxial films

We incorporate the experimentally deduced flux line potential well structure into the flux creep model. Application of this approach to the resistive transition in Bi2Sr2CaCu2O 8 epitaxial films explains the power law voltage-current characteristics and the nonlinear current dependence of the activation energy. The results cannot be accounted for by a transition into a superconducting vortex-glass phase.