Regensburg 2019 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 15: Magnetism Poster A
MA 15.2: Poster
Dienstag, 2. April 2019, 10:00–13:00, Poster E
Hall effect and magnetoelectric effect in systems with toroidal order — •Oliver Busch1, Börge Göbel2, and Ingrid Mertig1,2 — 1Institut für Physik, Martin-Luther-Universität, D-06120 Halle — 2Max-Planck-Institut für Materialforschung, D-06120 Halle
In systems that exhibit a toroidal moment the magnetoelectric effect arises due to antisymmetric time or space inversion symmetry [1]. The Hall effect and the magnetoelectric effect have already been predicted in metals without local inversion symmetry, described by a effective tight-binding model [2].
We examine a square-octagon lattice with regard to Hall effect and magnetoelectric effect based on a full sp-tight-binding model. Our model includes the description of coupling to the magnetic texture that causes toroidal order, spin-orbit coupling and sp-hybridization. We confirmed an asymmetric shift of the band structure in the direction of the toroidal moment that changes to a symmetric shift, if there is just sp-hybridization and spin-orbit coupling, but no toroidal order.
Breaking the combined TI-symmetry yields the topological Hall effect without spin-orbit coupling resp. the anomalous Hall effect in combination with spin-orbit coupling. Furthermore we show that the system gives rise to a transverse magnetoelectric Hall effect that vanishes for non toroidal order e.g. flux order. Last but not least we analyse the connection of the asymmetric shift and the magnetoelectric effect.
[1] N. Spaldin et al., J. Phys.: Condens. Matter 20, 434203 (2008).
[2] S. Hayami et al., Phys. Rev. B 90, 024432 (2014).