Frequency response of AC susceptibility in high temperature superconductors

Abstract Based on the thermal activation, considering the two most important energies, namely thermal activation energy, which drives the system to a more disordered state, and effective pinning energy, which keeps the system in order, a general description of the temperature dependence of resistivity under magnetic fields for high temperature superconductors has been deduced. The temperature dependence of resistivity can be expressed as ρ = ρ n (1− x ) s , with the energy ratio x = U eff ( T , B , J )/ k B T . This extended thermally activated model is a consistent description of the vortex glass theory. Our model is applied to the frequency response of AC susceptibility in YBCO superconductors; the results are in good agreement with the proposed model.