Nonmagnetic scattering induced suppression of superfluid density in Bi-2212

Nonlinear current-voltage ( IV ) characteristics of Bi-2212 observed in the presence of the nonmagnetic impurity have been explained incorporating the idea of Berezinskii-Kosterlitz - Thouless (BKT). An exponent ( η ) is extracted as a function of temperature ( T ) for several Bi 2− x Sr 2 CaCu 2− x Zn x O 8+ δ (Bi-2212) superconducting samples. Within the framework of the Ambegaokar-Halperin-Nelson-Siggia (AHNS) theory we have extracted the superfluid phase stiffness (SPS) as a function of T . A scaling between the SPS and critical temperature is observed. Strong suppression by the nonmagnetic impurity has been explained using the idea of localized phase fluctuations in the superconducting planes.