Title
Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures
Author
Faculty/Department
Faculty of Sciences. Physics
Publication type
article
Publication
Bristol ,
Subject
Physics
Source (journal)
Journal of physics : conference series. - Bristol
Volume/pages
150(2009) :5 , 4 p.
ISSN
1742-6588
1742-6596
Article Reference
052019
Carrier
E-only publicatie
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
We have used high resolution Hall probe microscopy to image vortex-antivortex (V-AV) 'molecules' induced in superconducting Pb films by the stray fields from square arrays of ferromagnetic Co/Pt dots. We have directly observed spontaneous V-AV pairs and studied how they interact with added 'free' (anti)fluxons in an applied magnetic field. We observe a rich variety of subtle phenomena arising from competing symmetries in our system which can either drive added antivortices to join AV shells around nanomagnets or stabilise the translationally symmetric AV lattice between the dots. Added vortices annihilate AV shells, leading eventually to a stable 'nulling' state with no free fluxons, which should exhibit a strongly (field-)enhanced critical current. At higher densities we actually observe vortex shells around the magnets, stabilised by the asymmetric anti-pinning potential. Our experimental findings are in good agreement with Ginzburg-Landau calculations.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/81a64e/23cadf8e.pdf
Handle