Dresden 2017 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 17: Ferroics - Domains, Domain Walls and Skyrmions IV
DF 17.1: Topical Talk
Thursday, March 23, 2017, 09:30–10:00, WIL B321
Magnetic and orbital excitations in the multiferroic skyrmion host GaV4S8 — Dieter Ehlers1, Zhe Wang1, Hans-Albrecht Krug von Nidda1, Vladimir Tsurkan1, Peter Lunkenheimer1, Istvan Kézsmárki2, Ioannis Stasinopoulos3, Dirk Grundler4, and •Alois Loidl1 — 1Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany — 2Department of Physics, Budapest University of Technology, Hungary — 3Lehrstuhl für Physik funktionaler Schichtsysteme, Physik Department, TUM, Munich, Germany — 4EPFL, Institut des matériaux, Lausanne, Switzerland
The lacunar spinel GaV4S8 exhibits a complex magnetic phase diagram, including ferromagnetic, cycloidal and Néel-type skyrmion phases [1,2]. Orbital ordering induces ferroelectricity [3] and spin-driven excess polarizations emerge in all magnetic phases, including skyrmions with ferroelectric polarization [2]. We present a detailed discussion on orbital and skyrmion excitations using THz and coplanar waveguide (CPW) absorption spectroscopy. At THz frequencies dipolar relaxations are strongly coupled to the orbital dynamics, establishing an orbitally-driven ferroelectric phase [3]. Using broadband CPW absorption spectroscopy we study the temperature and frequency dependence of skyrmion excitations [4].
[1] I. Kézsmárki et al., Nature Materials 14, 1116 (2015).
[2] E. Ruff et al., Science Advances 1, E1500916 (2015).
[3] Zhe Wang et al., Phys. Rev. Lett. 115, 207601 (2015).
[4] D. Ehlers et al., Phys. Rev. B 94, 014406 (2016).