Pinning and Vortexes' Dynamics in 3D Anisotropic Superconductors with Linear Defects

The problem of Abrikosov vortex depinning at low temperatures from extended c-oriented linear defect in 3D anisotropic (layered) superconductor under the surface transport current influence is solved. This problem is considered within the scope of classical mechanics as behaviour of an elastic vortex string, which is settled in the potential well of linear defect and exerted to exponentially distributed Lorentz force action within the screening layer of width lambda (lambda lambda(ab) is the London penetration depth) near the specimen surface. The mechanical stability problem is solved for the vortex string inside the potential well created by linear defect, and conditions of the instability threshold caused by attainment of depinning critical value of transport current are obtained. Besides, the vortex activation energy U-c(j) and corresponding current-voltage characteristic in the flux creep regime are calculated for superconductor with linear defects in a weak magnetic field. The obtained result's are also applied for calculation of critical current dependence on the disorientation angle in high-temperature superconductor (HTS) bicrystal with a dislocation low-angle [001] tilt grain boundary. The results of suggested model agree well with experimental data obtained on HTS materials.