title: Chirality-driven orbital magnetic moments as a new probe for topological magnetic structures.
abstract: When electrons are driven through unconventional magnetic structures, such as skyrmions, they experience emergent electromagnetic fields that originate several Hall effects. Independently, ground-state emergent magnetic fields can also lead to orbital magnetism, even without the spin-orbit interaction. The close parallel between the geometric theories of the Hall effects and of the orbital magnetization raises the question: does a skyrmion display topological orbital magnetism? Here we first address the smallest systems with nonvanishing emergent magnetic field, trimers, characterizing the orbital magnetic properties from first-principles. Armed with this understanding, we study the orbital magnetism of skyrmions and demonstrate that the contribution driven by the emergent magnetic field is topological. This means that the topological contribution to the orbital moment does not change under continuous deformations of the magnetic structure. Furthermore, we use it to propose a new experimental protocol for the identification of topological magnetic structures, by soft X-ray spectroscopy.
authors.affiliation: Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich &JARA, D-52425 Jülich, Germany.
authors.forename: Manuel
authors.identifier: 0000-0002-8835-5580
authors.initials: M
authors.lastname: Dos Santos Dias
authors.affiliation: Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich &JARA, D-52425 Jülich, Germany.
authors.forename: Juba
authors.initials: J
authors.lastname: Bouaziz
authors.affiliation: Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich &JARA, D-52425 Jülich, Germany.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bouhassoune
authors.affiliation: Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich &JARA, D-52425 Jülich, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Blügel
authors.affiliation: Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich &JARA, D-52425 Jülich, Germany.
authors.forename: Samir
authors.identifier: 0000-0003-2573-2841
authors.initials: S
authors.lastname: Lounis