Large topological Hall effect in the non-collinear phase of an antiferromagnet

Christoph Sürgers; Gerda Fischer; Patrick Winkel; Hilbert V Löhneysen

doi:10.1038/ncomms4400

Large topological Hall effect in the non-collinear phase of an antiferromagnet

Nat Commun. 2014 Mar 5:5:3400. doi: 10.1038/ncomms4400.

Authors

Christoph Sürgers¹, Gerda Fischer², Patrick Winkel², Hilbert V Löhneysen³

Affiliations

¹ 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.
² Karlsruhe Institute of Technology, Physikalisches Institut, PO Box 6980, 76049 Karlsruhe, Germany.
³ 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.

PMID: 24594621
DOI: 10.1038/ncomms4400

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.

Publication types

Research Support, Non-U.S. Gov't