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arXiv · 2406.05319

Spin and lattice dynamics of a van der Waals antiferromagnet MnPSe$_3$

Junbo Liao·Zhentao Huang·Yanyan Shangguan·Bo Zhang·Shufan Cheng·Hao Xu·Ryoichi Kajimoto·Kazuya Kamazawa·Song Bao·Jinsheng Wen
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Abstract

Antiferromagnetic van der Waals family $\rm \textit{M}P\textit{X}_{3}\ (M=Fe,\ Mn,\ Co,\text{ and}\ Ni; X=S\text{ and}\ Se)$ have attracted significant research attention due to the possibility of realizing long-range magnetic order down to the monolayer limit. Here, we perform inelastic neutron scattering measurements on single crystal samples of MnPSe$_3$, a member of the $\rm \textit{M}P\textit{X}_{3}$ family, to study the spin dynamics and determine the effective spin model. The excited magnon bands are well characterized by a spin model, which includes a Heisenberg term with three intraplane exchange parameters ($J_{1}=-0.73$~meV, $J_{2}=-0.014$~meV, $J_{3}=-0.43$~meV) and one interplane parameter ($J_{c}=-0.054$~meV), and an easy-plane single-ion anisotropy term ($D=-0.035$~meV). Additionally, we observe the intersection of the magnon and phonon bands but no anomalous spectral features induced by the formation of magnon-phonon hybrid excitations at the intersecting region. We discuss possible reasons for the absence of such hybrid excitations in MnPSe$_3$.

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Junbo Liao, Zhentao Huang, Yanyan Shangguan, Bo Zhang, Shufan Cheng, Hao Xu, Ryoichi Kajimoto, Kazuya Kamazawa, Song Bao, Jinsheng Wen. 2024-06-08. Spin and lattice dynamics of a van der Waals antiferromagnet MnPSe$_3$. https://doi.org/10.1103/physrevb.109.224411

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