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arXiv · 2412.21003

Signatures of Kitaev interactions in the van der Waals ferromagnet VI3

Yiqing Gu·Yimeng Gu·Feiyang Liu·Seiko Ohira-Kawamura·Naoki Murai·Jun Zhao
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Abstract

Materials manifesting the Kitaev model, characterized by bond-dependent interactions on a honeycomb lattice, can host exotic phenomena like quantum spin liquid states and topological magnetic excitations. However, finding such materials remains a formidable challenge. Here, we report high-resolution inelastic neutron scattering measurements performed on VI3, a van der Waals ferromagnetic Mott insulator, covering a wide range of reciprocal space. Our measurements unveil highly anisotropic magnetic excitations in momentum space. Through a comprehensive comparative analysis of various models that incorporate diverse symmetry-allowed magnetic interactions, we find the observed excitations are well captured by a model with a large bond-dependent Kitaev interaction. These results not only help to understand the intriguing properties of VI3, such as the pronounced anomalous thermal Hall effects and strong pressure/structure dependence of magnetism, but also open a new avenue for exploring Kitaev physics.

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Yiqing Gu, Yimeng Gu, Feiyang Liu, Seiko Ohira-Kawamura, Naoki Murai, Jun Zhao. 2024-12-30. Signatures of Kitaev interactions in the van der Waals ferromagnet VI3. https://doi.org/10.1103/physrevlett.132.246702

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