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arXiv · 2107.03928

Nontrivial temperature dependence of magnetic anisotropy in multiferroics Ba$_2$MnGe$_2$O$_7$

Shunsuke Hasegawa·Shohei Hayashida·Shinichiro Asai·Masato Matsuura·Zaliznyak Igor·Takatsugu Masuda
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Abstract

We measured the temperature dependences of the static magnetization and the spin excitation in a square-lattice multiferroics Ba$_2$MnGe$_2$O$_7$. An anisotropy gap of the observed low energy mode is scaled by electric polarization rather than a power of sublattice moment. Spin nematic interaction in effective spin Hamiltonian, which is equivalent to interaction of electric polarization, is responsible for the easy-axis anisotropy. The nontrivial behavior of the anisotropy gap can be rationalized as change of the hybridized $d$-$p$ orbital with temperature, leading to the temperature dependence of the spin nematic interaction.

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Shunsuke Hasegawa, Shohei Hayashida, Shinichiro Asai, Masato Matsuura, Zaliznyak Igor, Takatsugu Masuda. 2021-07-08. Nontrivial temperature dependence of magnetic anisotropy in multiferroics Ba$_2$MnGe$_2$O$_7$. https://arxiv.org/abs/2107.03928

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