I-V Characteristics of High Temperature Superconductors with Columnar Defects

The vortex glass transition in the presence of columnar defects is studied by Monte Carlo simulations of a vortex loop model, suggested by the analogy to the $T=0$ superconductor-insulator transition for dirty bosons in (2+1)D. From finite-size scaling analysis of the $I$-$V$ characteristic we find two dynamical exponents describing the non-equilibrium behavior. We obtain $z_{\perp} = 6 \pm 0.5$ and $z_{\parallel} = 4 \pm 0.5$ when the current is applied perpendicular and parallel to the columnar defects respectively.