title: Reduced-dimensionality-induced helimagnetism in iron nanoislands.
abstract: Low-dimensionality in magnetic materials often leads to noncollinear magnetic order, such as a helical spin order and skyrmions, which have received much attention because of envisioned applications in spin transport and in future data storage. Up to now, however, the real-space observation of the noncollinear magnetic order has been limited mostly to systems involving a strong spin-orbit interaction. Here we report a noncollinear magnetic order in individual nanostructures of a prototypical magnetic material, bilayer iron islands on Cu (111). Spin-polarized scanning tunnelling microscopy reveals a magnetic stripe phase with a period of 1.28 nm, which is identified as a one-dimensional helical spin order. Ab initio calculations identify reduced-dimensionality-enhanced long-range antiferromagnetic interactions as the driving force of this spin order. Our findings point at the potential of nanostructured magnets as a new experimental arena of noncollinear magnetic order stabilized in a nanostructure, magnetically decoupled from the substrate.
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, Halle 06120, Germany.
authors.forename: S-H
authors.initials: SH
authors.lastname: Phark
authors.affiliation: 1] Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, Halle 06120, Germany [2] Laboratório de Filmes Finos e Superfícies, Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil.
authors.forename: J A
authors.initials: JA
authors.lastname: Fischer
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, Halle 06120, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Corbetta
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, Halle 06120, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Sander
authors.affiliation: Department of Physics Engineering, Mie University, Tsu, Mie 514-8507, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, Halle 06120, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kirschner