Effects of columnar pins on flux line dynamics.

The effects of columnar pins on the flux lines in a model high-T c superconductor in an applied field are studied through Monte Carlo simulations. An analytic solution for a single line case is obtained and compared with the simulation results. By introducing a tilted potential, we study simulated «I-V» characteristics and the results indicate a distinct scaling behavior above and below the depinning temperature. We introduce a diverging length scale measured in terms of a «retrapping length» to analyze self-similar behavior across the sharp depinning crossover