16 research outputs found
Vortex cutting in superconductors.
Vortex cutting and reconnection is an intriguing and still-unsolved problem central to many areas of classical
and quantum physics, including hydrodynamics, astrophysics, and superconductivity. Here, we describe a
comprehensive investigation of the crossing of magnetic vortices in superconductors using time dependent
Ginsburg-Landau modeling. Within a macroscopic volume, we simulate initial magnetization of an anisotropic
high temperature superconductor followed by subsequent remagnetization with perpendicular magnetic fields,
creating the crossing of the initial and newly generated vortices. The time resolved evolution of vortex lines as they
approach each other, contort, locally conjoin, and detach, elucidates the fine details of the vortex-crossing scenario
under practical situations with many interacting vortices in the presence of weak pinning. Our simulations also
reveal left-handed helical vortex instabilities that accompany the remagnetization process and participate in the
vortex crossing events
Magneto-optical Imaging of Transport Current Densities in Superconductors
Direct imaging of the paths of transport currents in superconductors creates many new possibilities for exploring the basic features of vortex pinning mechanisms and for improving the performance of superconducting materials. A technique for imaging the path and magnitude of the transport current density flowing in superconductors is described. Results are given for a 37-filament BSCCO 2223 powder-in-tube wire, showing a highly inhomogeneous current path within the filaments