DIRECT NUMERICAL EXPERIMENT ON 2-DIMENSIONAL PINNING DYNAMICS OF A 3-DIMENSIONAL VORTEX LINE IN LAYERED SUPERCONDUCTORS

We clarify structures and dynamics of tilted vortices in the T-c modul ated three-dimensional (3D) layered superconductor by performing a dir ect numerical simulation of the time-dependent Ginzburg-Landau equatio n coupled with Maxwell's equation. The change of vortex dynamics from a rigid and straight vortex line in the low temperature region to a st epwise vortex in the high temperature region is observed. We investiga te vortex pinning for columnar and point defects, and find that a flex ible deformation of vortex segments parallel to the layer in the 3D co ntinuous stepwise vortex is reinforced in the presence of pinning cent ers and leads to 2D pinning dynamics. Also, this increased flexibility is shown to bring about more effective vortex pinning.