Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 73: Low-Dimensional Systems: Topological Order
TT 73.9: Vortrag
Donnerstag, 10. März 2016, 17:30–17:45, H19
Magnetic behaviour of the honeycomb antiferromagnet BaNi2V2O8 — •Ekaterina Klyushina1,2, Bella Lake1,2, Nazmul Islam1, Bastian Klemke1, Astrid Schneidewind3, Jitae Park3, and Martin Mansson4 — 1Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany — 2Institut für Festkörperphysik, Technische Universität Berlin, Berlin, Germany — 3Heinz Maier-Leibnitz Zentrum, TU München, Garching, Germany — 4Paul Scherrer Institute, Switzerland
Here we present our recent investigations of a spin-1 honeycomb antiferromagnetic BaNi2V2O8 which is a highly 2D antiferromagnet with XY anisotropy making this compound a potential candidate for the Berezinsky-Kosterliz-Thouless topological phase transition [1,2]. Single crystal inelastic neutron scattering measurements in the honeycomb plane at 4 K reveal that the magnetic excitations extend from 0.3-26 meV and consist of two anisotropy-split gapped modes with gaps of 0.3 meV and 3.3 meV arising from the anisotropy within the a-b plane and XY anisotropy respectively . The excitations agree well with simulations based on linear spin - wave theory and are completely dispersionless in the out-of-plane direction suggesting negligible interplane coupling in spite of the long range magnetic order below TN = 48 K. A detailed investigation of the order parameter and correlation length are presented and compared to various theories.
J. M. Kosterlitz, D. J. Thouless J. Phys. C 6, 1181 (1973)
A. Cuccoli et al., PRB 67, 104414 (2003)