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Symmetry of Multiferroicity in a Frustrated Magnet TbMn$_2$O$_5$

J. Okamoto·D. J. Huang·C. -Y. Mou·K. S. Chao·H. -J. Lin·S. Park·S-W. Cheong·C. T. Chen
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Abstract

Based on measurements of soft x-ray magnetic scattering and symmetry considerations, we demonstrate that the magnetoelectric effect in TbMn$_2$O$_5$ arises from an internal field determined by $\vec{S}_{\vec{q}} \times {\vec{S}_{-\vec{q}}}$ with $\vec{S}_{\vec{q}}$ being the magnetization at modulation vector $\vec{q}$, whereas the magneto-elastic effect in the exchange energy governs the response to external electric fields. Our results set fundamental symmetry constraints on the microscopic mechanism of multiferroicity in frustrated magnets.

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J. Okamoto, D. J. Huang, C. -Y. Mou, K. S. Chao, H. -J. Lin, S. Park, S-W. Cheong, C. T. Chen. 2007-03-09. Symmetry of Multiferroicity in a Frustrated Magnet TbMn$_2$O$_5$. https://arxiv.org/abs/cond-mat/0703234

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