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arXiv · 2502.05422

Nonmagnetic ground state of marcasite FeTe$_{2}$: The competition between crystal field splitting and on-site Coulomb repulsion

Yue-Fei Hou·Zhibin Shao·Minghu Pan·Shiyang Wu·Fawei Zheng·Zhen-Guo Fu·Ping Zhang
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Abstract

The magnetic ground states in crystalline systems are significant for both fundamental condensed matter physics and practical materials engineering. Marcasite FeTe$_{2}$, characterized as a small-gap semiconductor, exhibits anomalous magnetic behaviors in low-temperature experiments. In this study, first-principles density functional theory calculations combined with scanning tunneling microscopy/spectroscopy are employed to investigate the magnetic ground state of marcasite FeTe$_{2}$. It is revealed that the competition between crystal field splitting and on-site Coulomb repulsion plays the key role in the formation of localized magnetic moments in FeTe$_{2}$. The ground state of FeTe$_{2}$ bulk is confirmed to be nonmagnetic, while the magnetic responses of FeTe$_{2}$ observed at low temperature are suggested to be related to the magnetic Fe atoms on the crystal surfaces. Our work proposes a straightforward competing mechanism for determining ground-state magnetism of various localized-moment crystalline systems.

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Yue-Fei Hou, Zhibin Shao, Minghu Pan, Shiyang Wu, Fawei Zheng, Zhen-Guo Fu, Ping Zhang. 2025-02-08. Nonmagnetic ground state of marcasite FeTe$_{2}$: The competition between crystal field splitting and on-site Coulomb repulsion. https://arxiv.org/abs/2502.05422

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