FeTaX2: A ferrimagnetic quantum anomalous Hall insulator

Fuente: arXiv
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Main Authors: Jiang, Yadong, Wang, Huan, Wang, Jing
Format: Preprint
Published: 2025
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author Jiang, Yadong
Wang, Huan
Wang, Jing
author_facet Jiang, Yadong
Wang, Huan
Wang, Jing
contents We propose that the van der Waals layered ternary transition metal chalcogenides FeTa$X_2$ ($X=$ S, Se, Te) as a new family of ferrimagnetic quantum anomalous Hall insulators with a sizable bulk gap and high Chern number $C=-2$. The magnetic order arises primarily from Fe atoms, whose strong ferromagnetic exchange induces moments on neighboring Ta sites. The large topological gap originates from a \emph{deep} $s$-$d$-type band inversion between spin-down Ta $d_{z^2}$ and $d_{xy}$ orbitals near the Fermi level-a mechanism unique to $d$-orbital systems. Remarkably, the Curie temperature of monolayer FeTa$X_2$ is predicted to significantly exceed that of monolayer MnBi$_2$Te$_4$. Furthermore, both the Curie temperature and topological gap scale positively with the spin-orbit coupling strength of the $d$ electrons, suggesting a common physical origin. Owing to its structural similarity to Fe$X$ superconductors and reduced net magnetization, FeTa$X_2$ further offers a promising platform for realizing chiral topological superconductivity. These findings, if realized experimentally, could open new avenues for the research and application of topological quantum physics.
format Preprint
id arxiv_https___arxiv_org_abs_2506_07125
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle FeTaX2: A ferrimagnetic quantum anomalous Hall insulator
Jiang, Yadong
Wang, Huan
Wang, Jing
Mesoscale and Nanoscale Physics
Materials Science
We propose that the van der Waals layered ternary transition metal chalcogenides FeTa$X_2$ ($X=$ S, Se, Te) as a new family of ferrimagnetic quantum anomalous Hall insulators with a sizable bulk gap and high Chern number $C=-2$. The magnetic order arises primarily from Fe atoms, whose strong ferromagnetic exchange induces moments on neighboring Ta sites. The large topological gap originates from a \emph{deep} $s$-$d$-type band inversion between spin-down Ta $d_{z^2}$ and $d_{xy}$ orbitals near the Fermi level-a mechanism unique to $d$-orbital systems. Remarkably, the Curie temperature of monolayer FeTa$X_2$ is predicted to significantly exceed that of monolayer MnBi$_2$Te$_4$. Furthermore, both the Curie temperature and topological gap scale positively with the spin-orbit coupling strength of the $d$ electrons, suggesting a common physical origin. Owing to its structural similarity to Fe$X$ superconductors and reduced net magnetization, FeTa$X_2$ further offers a promising platform for realizing chiral topological superconductivity. These findings, if realized experimentally, could open new avenues for the research and application of topological quantum physics.
title FeTaX2: A ferrimagnetic quantum anomalous Hall insulator
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2506.07125