Novel optical properties of spin-wave excitations in non-centrosymmetric oxides: the case of Ba2CoGe2O7

  • Sándor BordácsEmail author
  • Yoshinori Tokura
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 159)


We have recently demonstrated that multiferroics host exotic optical phenomena, such as non-reciprocal directional dichroism [1] and natural optical activity [2], for spin-wave excitations owing to the strong dynamic magnetoelectric coupling. The observed large optical anisotropies can pave the way for novel THz applications e.g. unidirectional waveguides or polarization rotators.


Chiral Phase Ferroelectric Polarization Natural Optical Activity Magnon Mode Molecular Light Scattering 
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This work was supported by the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program), Japan.


  1. 1.
    I. Kézsmárki, et al., “Enhanced Directional Dichroism of Terahertz Light in Resonance with Magnetic Excitations of the Multiferroic Ba2CoGe2O7 Oxide Compound” Phys. Rev. Lett. 106, 057403 (2011).Google Scholar
  2. 2.
    S. Bordács, et al., “Chirality of matter shows up via spin excitations” Nat. Phys. 8, 734-738 (2012).Google Scholar
  3. 3.
    L. Barron, “Molecular Light Scattering and Optical Activity”, (Cambridge, 2004), Chap. 1, pp. 22-23.Google Scholar
  4. 4.
    H. Murakawa et al., “Ferroelectricity Induced by Spin-Dependent Metal-Ligand Hybridization in Ba2CoGe2O7” Phys. Rev. Lett. 105, 137202 (2010).Google Scholar
  5. 5.
    S. Miyahara, N. Furukawa, “Theory of Magnetoelectric Resonance in Two-Dimensional S = 3/2 Antiferromagnet Ba2CoGe2O7” J. Phys. Soc. Jpn. 80, 073708 (2011).Google Scholar
  6. 6.
    K. Penc et al., “Spin-Stretching Modes in Anisotropic Magnets: Spin-Wave Excitations in the Multiferroic Ba2CoGe2O7” Phys. Rev. Lett. 108, 257203 (2012).Google Scholar
  7. 7.
    Y. Takahashi et al., “Magnetoelectric Resonance with Electromagnons in a Perovskite Helimagnet” Nat. Phys. 8, 121-125 (2011).Google Scholar
  8. 8.
    D. Szaller, S. Bordács, I. Kézsmárki, “Symmetry Conditions for Nonreciprocal Light Propagation in Magnetic Crystals” Phys. Rev. B 87, 014421 (2013).Google Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Quantum Phase-Electronics Center, Department of Applied PhysicsThe University of TokyoBunkyo-kuJapan
  2. 2.RIKEN Center for Emergent Matter Science (CEMS)WakoJapan

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