SURFACE INSTABILITIES AND PLASTIC-DEFORMATION OF VORTEX LATTICES

We investigate the stability of the vortex configuration in thin super conducting strips under an applied current analytically and by numeric al simulation of the time-dependent Ginzburg-Landau equation. We show that the stationary vortex lattice becomes unstable with respect to lo ng-wavelength perturbations above some critical current I-c. We find t hat at currents slightly exceeding I-c the vortex phase develops plast ic flow, where large coherent pieces of the lattice are separated by l ines of defects and slide with respect to each other (ice-floe-like mo tion). At elevated current a transition to elastic flow is observed.