Pinning of Multiply Quantized Vortices in Two-dimensional Superconductors by Magnetic Dots
Abstract
In recent years several laboratories have observed sharp oscillations of magnetoresistivity as a function of magnetic field in thin superconducting films deposited over a regular array of microscopic ( ~ 0.1 μm) magnetic dots. The oscillations persist to relatively high orders of the geometrical matching field. We use the London theory to describe interaction between the superconductor and the magnetic dots. Superconducting vortices interact magnetically with the dots; the interaction being attractive or repulsive depending on the mutual orientation of the magnetic fields. When the interaction is attractive, a single dot can pin multiple vortices, up to a saturation number, as a single multiply quantized vortex. The calculated saturation number compares well with the observed maximum order of the matching effects. We also study the system away from the exact matching field and explore different geometries for increased pinning over a range of applied fields.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2000
- Bibcode:
- 2000APS..MARA12011S