Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 8: Superconductivity - Poster Session
TT 8.45: Poster
Montag, 26. März 2007, 14:00–17:45, Poster A
Transport of magnetic flux quanta by Surface Acoustic Waves — •Munise Rakel, Fabian Jachmann, and Carsten Hucho — Paul-Drude-Institut, Hausvogteiplatz 5-7, 10117 Berlin
We report on the interaction between a traveling surface acoustic wave (SAW) and the ensemble of magnetic flux quanta (vortices) in a type II superconductor in the Shubnikov phase. The possibility of manipulating the motion and density of single flux quanta by a dynamic external parameter (no direct contact) has far reaching technological consequences. Here we investigate a thin film of superconducting YBa2Cu3O7 on a piezoelectric substrate. The SAWs were generated by applying an RF-current into interdigital transducers (IDTs). This results in a DC-voltage peak in the superconducting film near the critical temperature Tc which shows both symmetric and antisymmetric contributions in the presence of a magnetic field. While the symmetric background can be related to the well known ac/dc-conversion effect, the antisymmetric part is ascribed to the SAW induced directed motion of vortices. The ultrasonic strain wave itself acts like a dynamic pinning grid to which the vortices are forced to couple. This SAW related vortex drag is, therefore, most prominent in a very narrow temperature and field range right at the boundary between the vortex glass phase and the thermally activated flux flow regime.