Regensburg 1998 – scientific programme

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TT: Tiefe Temperaturen

TT 9: Vortex-Dynamik

TT 9.2: Talk

Tuesday, March 24, 1998, 10:30–10:45, H 8

Crossover from stiff to elastic vortex creep in superconducting multilayer structures — •T. Dr"ose and C. de Morais Smith — I. Institut für theoretische Physik, Jungiusstraße 9, D-20355 Hamburg

We calculate the thermal creep rate of a stack of pancake vortices escaping from a columnar defect perpendicular to the planes of a layered superconductor with finite thickness. We show that a crossover from two- to three-dimensional creep can be tuned by either varying the number of superconducting layers, the external driving current or the pinning strength of the defect. In the two-dimensional regime, the vortex stack is creeping as a stiff object, whereas the three-dimensional behavior is due to bent configurations using elasticity to lower their activation energy by nucleating at the surface.