IV CHARACTERISTICS OF HIGH-TEMPERATURE SUPERCONDUCTORS WITH COLUMNAR DEFECTS

The vortex glass transition in the presence of columnar defects is stu died by Monte Carlo simulations of a vortex loop model, suggested by t he analogy to the T = 0 superconductor-insulator transition for dirty bosons in (2+1) dimensions. Rom finite-size scaling analysis of the I- V characteristic we find two dynamical exponents describing the nonequ ilibrium behavior. We obtain z(perpendicular-to) = 6 +/- 0.5 and z(par allel-to) = 4 +/- 0.5 when the current is applied perpendicular and pa rallel to the columnar defects, respectively.