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arXiv · 2312.13911

Altermagnetic ferroelectric LiFe2F6 and spin-triplet excitonic insulator phase

Peng-Jie Guo·Yuhao Gu·Ze-Feng Gao·Zhong-Yi Lu
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Abstract

Altermagnetism is a new magnetic phase with k-dependent spin polarization and may exist in an insulating state with a high N\'eel temperature. This provides a new opportunity to obtain both spin and electric polarization in one material. Here, based on symmetry analysis and the first-principles electronic structures calculations, we predict that LiFe2F6 is a d-wave altermagnetic and charge-ordering-mediated ferroelectric material. Moreover, the LiFe2F6 transforms into a ferrimagnetic and ferroelectric phase with strong magnetoelectric coupling under biaxial compressive strain. Interestingly, the spins of the valence band and the conduction band are opposite in ferrimagnetic LiFe2F6, which facilitates a simultaneous spin-triplet excitonic insulator phase. More importantly, the spin-triplet excitons with spin 1 and -1 can be switched by electric fields in ferrimagnetic LiFe2F6 due to strong magnetoelectric coupling. Due to the abundance of novel physical properties, LiFe2F6 will certainly attract a wide range of theoretical and experimental interest.

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Peng-Jie Guo, Yuhao Gu, Ze-Feng Gao, Zhong-Yi Lu. 2023-12-21. Altermagnetic ferroelectric LiFe2F6 and spin-triplet excitonic insulator phase. https://arxiv.org/abs/2312.13911

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