Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 48: Superconductivity: Heterostructures, Andreev Scattering, Proximity Effect, Vortices
TT 48.13: Vortrag
Freitag, 30. März 2012, 12:45–13:00, H 2053
Superconducting vortex dynamics in cylindrical Nb micro- and nanotubes — •Vladimir M. Fomin1, Roman O. Rezaev1,2, and Oliver G. Schmidt1,3 — 1Institute for Integrative Nanosciences, IFW-Dresden, D-01069 Dresden, Germany — 2Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634050 Tomsk, Russia — 3Material Systems for Nanoelectronics, Chemnitz University of Technology, D-09107 Chemnitz, Germany
Advancements in fabrication of rolled-up micro- and nanotubes including superconductor layers (e.g., InGaAs/GaAs/Nb) open new ways for investigation of the vortex matter in superconductors with curved geometries. Geometry determines the dynamics of vortices in the presence of transport currents in open superconductor micro- and nanotubes subject to a magnetic field orthogonal to the axis. Vortices nucleate periodically at one edge of the tube, subsequently move along the tube under the action of the Lorentz force and denucleate at the opposite edge of the tube. Characteristic times of nonequilibrium vortex dynamics in an open tube are efficiently controlled by the tube radius. The magnetic field, at which the vortices begin to nucleate at the edge of the structure, is increased several times by rolling up a planar film in a tube. This effect is caused not only by a spatial dependence of the magnetic field component normal to the cylindrical surface, but also by correlations between the states of the superconducting order parameter in the opposite areas of the cylindrical surface.