title: Local Observation of Field Polarity Dependent Flux Pinning by Magnetic Dipoles.
abstract: A scanning Hall probe microscope is used to study flux pinning in a thin superconducting Pb film covering a square array of single-domain Co dots with in-plane magnetization. We show that single flux quanta of opposite sign thread the superconducting film below T(c) at the opposite poles of these dipoles. Depending on the polarity of the applied field, flux lines are attracted to a specific pole of the dipoles, due to the direct interaction with the vortexlike structures induced by the local stray field.
authors.affiliation: Laboratorium voor Vaste-Stoffysica en Magnetisme, K. U. Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
authors.lastname: Van Bael MJ
authors.initials: J
authors.lastname: Bekaert
authors.initials: K
authors.lastname: Temst
authors.lastname: Van Look L
authors.initials: VV
authors.lastname: Moshchalkov
authors.initials: Y
authors.lastname: Bruynseraede
authors.initials: GD
authors.lastname: Howells
authors.initials: AN
authors.lastname: Grigorenko
authors.initials: SJ
authors.lastname: Bending
authors.initials: G
authors.lastname: Borghs