POWER-LAW RESISTIVE BEHAVIOR OF 2-DIMENSIONAL JOSEPHSON JUNCTION ARRAY WITH BOND DEFECTS - DYNAMIC SIMULATION AND ITS RELEVANCE TO HIGH-TC OXIDES

Nonlinear electric resistivity of the two-dimensional (2D) Josephson junction array with bond defects (defect density p) is calculated directly using the Langevin simulation technique. It is found that both the current-voltage (I-V) characteristics and the p-V resistive behavior at low temperatures obey power-laws with continuously varying exponents: V proportional-to I-alpha-(p) and V proportional-to p-beta-(I). Computational results are quite similar to those observed experimentally in the ion irradiation effect on high-T(c) oxides. The ion irradiation is thought to create random defects in the 2D intrinsic weak-link structure which is peculiar to the high-T(c) oxide superconductor. It is suggested that the vortex-antivortex pair excitation and its transport property in 2D media with bond disorder are crucial for the defect-dependent power-law.