Interaction of two-dimensional vortices with linear ion tracks in the highly anisotropic layered cuprates

The effects of linear, ion-track pinning centers on the resistive dissipation and critical current density (Formula presented) are investigated in the highly anisotropic Tl-cuprate superconductors. At some fields, the data rigorously follow two-dimensional (2D) scaling without irradiation, but the irradiated samples show a dip in dissipation for fields parallel to the ion tracks, indicating 3D effects. Also the effective pinning field of the defects is found to be temperature dependent: it rises to many times the ion-dose field for temperatures well below (Formula presented). These results imply that vortex-vortex interactions need to be included for a quantitative understanding.