title: Dissociation of vortex stacks into fractional-flux vortices.
abstract: We discuss the zero field superconducting phase transition in a finite system of magnetically coupled superconducting layers. Transverse screening is modified by the presence of other layers resulting in topological excitations with fractional flux. Vortex stacks trapping a full flux and present at any finite temperature undergo a dissociation transition which corresponds to the depairing of fractional-flux vortices in individual layers. We propose an experiment with a bilayer system allowing us to identify the dissociation of bound vortex molecules.
authors.affiliation: Theoretische Physik, ETH-Hönggerberg, CH-8093 Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: De Col
authors.forename: V B
authors.initials: VB
authors.lastname: Geshkenbein
authors.forename: G
authors.initials: G
authors.lastname: Blatter