Non-linear transport phenomena along the c-axis in single crystalline Bi2Sr2CaCu2O8+δ

Abstract The c-axis current-voltage ( I – V ) characteristics have been investigated in magnetic fields up to 6 T applied along the c-axis. A sharp transition at J c c from superconducting to normal state in zero magnetic field decreases rapidly under magnetic fields up to a critical field H ∗ ≈ 0.2 T ∼ 0.3 T, while the sharpness of the transition is lost above H ∗ . This phenomenon is considered as the breakdown of the Josephson coupling (decoupling effect) between the superconducting CuO 2 layers due to dissociation of vortex lines into pancake vortices.