Relationship between the surface resistance and depairing current density of superconductors

We have examined the relationship between the surface resistance and the depairing current density of superconductors. From the two-fluid model and the relationship between the depairing current density and the thermodynamic critical field, we can show that the surface resistance is in inverse proportion to the depairing current density. We also experimentally examined the correlation between the surface resistance and the critical current density of YBCO thin films, and found that the surface resistance is in inverse proportion to the critical current density. The results mean that our theoretical analysis is suitable for predicting the correlation between the surface resistance and the critical current density.