title: Coupled vortex oscillations in spatially separated permalloy squares.
abstract: We experimentally study the magnetization dynamics of pairs of micron-sized permalloy squares coupled via their stray fields. The trajectories of the vortex cores in the Landau-domain patterns of the squares are mapped in real space using time-resolved scanning transmission x-ray microscopy. After excitation of one of the vortex cores with a short magnetic-field pulse, the system behaves like coupled harmonic oscillators. The coupling strength depends on the separation between the squares and the configuration of the vortex-core polarizations. Considering the excitation via a rotating in-plane magnetic field, it can be understood that only a weak response of the second vortex core is observed for equal core polarizations.
authors.affiliation: Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, 20355 Hamburg, Germany. andreas.vogel@physnet.uni-hamburg.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Vogel
authors.forename: Thomas
authors.initials: T
authors.lastname: Kamionka
authors.forename: Michael
authors.initials: M
authors.lastname: Martens
authors.forename: André
authors.initials: A
authors.lastname: Drews
authors.forename: Kang Wei
authors.initials: KW
authors.lastname: Chou
authors.forename: Tolek
authors.initials: T
authors.lastname: Tyliszczak
authors.forename: Hermann
authors.initials: H
authors.lastname: Stoll
authors.forename: Bartel
authors.initials: B
authors.lastname: Van Waeyenberge
authors.forename: Guido
authors.initials: G
authors.lastname: Meier