Effect of impurity scattering on upper critical field of unconventional superconductors

Abstract The effect of Impurity scattering on upper critical fields in the axial state (P) and the hybrid state (D) is studied within weak coupling model. Unlike S-wave superconductor, impurity scattering suppresses both the transition temperature T c and upper critical field H c2 (T). However, when H c2 (x,T) / H c2 (x,o) is plotted against T/ T c (x), the curves for different x(=0.5669 (τT c0 ) −1 ) almost collapse into a single curve. This behavior should give another test of unconventional superconductors.