title: Large topological Hall effect in the non-collinear phase of an antiferromagnet.
abstract: Non-trivial spin arrangements in magnetic materials give rise to the topological Hall effect observed in compounds with a non-centrosymmetric cubic structure hosting a skyrmion lattice, in double-exchange ferromagnets and magnetically frustrated systems. The topological Hall effect has been proposed to appear also in presence of non-coplanar spin configurations and thus might occur in an antiferromagnetic material with a highly non-collinear and non-coplanar spin structure. Particularly interesting is a material where the non-collinearity develops not immediately at the onset of antiferromagnetic order but deep in the antiferromagnetic phase. This unusual situation arises in non-cubic antiferromagnetic Mn5Si3. Here we show that a large topological Hall effect develops well below the Néel temperature as soon as the spin arrangement changes from collinear to non-collinear with decreasing temperature. We further demonstrate that the effect is not observed when the material is turned ferromagnetic by carbon doping without changing its crystal structure.
authors.affiliation: 1] Karlsruhe Institute of Technology, Physikalisches Institut, PO Box 6980, 76049 Karlsruhe, Germany [2] Karlsruhe Institute of Technology, DFG Center for Functional Nanostructures, PO Box 6980, 76049 Karlsruhe, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Sürgers
authors.affiliation: Karlsruhe Institute of Technology, Physikalisches Institut, PO Box 6980, 76049 Karlsruhe, Germany.
authors.forename: Gerda
authors.initials: G
authors.lastname: Fischer
authors.affiliation: Karlsruhe Institute of Technology, Physikalisches Institut, PO Box 6980, 76049 Karlsruhe, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Winkel
authors.affiliation: 1] Karlsruhe Institute of Technology, Physikalisches Institut, PO Box 6980, 76049 Karlsruhe, Germany [2] Karlsruhe Institute of Technology, DFG Center for Functional Nanostructures, PO Box 6980, 76049 Karlsruhe, Germany [3] Karlsruhe Institute of Technology, Institut für Festkörperphysik, PO Box 3640, 76021 Karlsruhe, Germany.
authors.forename: Hilbert V
authors.initials: HV
authors.lastname: Löhneysen