Universal scaling for both isotropic and anisotropic irradiated superconductors Original Research Article

Current–voltage characteristics are investigated by transport measurements on heavy-ion irradiated Bi2Sr2CaCu2O8+δ (γ=380), Bi1.8Pb0.2Sr2CaCu2O8+δ (γ=60) and isotropic (K,Ba)BiO3 single crystals. In the range of magnetic fields from Bϕ/10 to Bϕ (where Bϕ is the matching field), the same scaling functions can be used to describe the transition in these systems. We obtain ν⊥=1.1±0.1, z=5.3±0.2 using α (≡ν∥/ν⊥)=2, in good agreement with numerical simulations for the case of strongly screened vortex line interactions. The most important finding is that the scaling laws of the I–V characteristics in these systems could be the same despite the difference in anisotropy.