Tuning the magnetic anisotropy and topological phase with electronic correlation in single-layer H-FeBr$_2$

TL;DR

This study explores how electronic correlation influences magnetic anisotropy and topological phases in single-layer H-FeBr$_2$, revealing tunable properties and phase transitions relevant for spintronics and valleytronics applications.

Contribution

It demonstrates the impact of electronic correlation on magnetic anisotropy and topological phases in single-layer H-FeBr$_2$, highlighting the role of element-specific spin-orbital interactions.

Findings

Magnetic anisotropy energy shows non-monotonic behavior with correlation strength.

Electronic correlation induces band inversions and topological phase transitions.

System exhibits quantum anomalous valley Hall effect.

Abstract

Electronic correlation can strongly influence the electronic properties of two-dimensional (2D) materials with open d- or f-orbitals. Herein, by taking single-layer (SL) H-FeBr$_2$ as a representative of the SL H-FeX$_2$ (X=Cl, Br, I) family, we investigated the electronic correlation effects in the magnetic anisotropy and electronic topology of such a system based on first-principles calculations with DFT+\textit{U} approach. Our result is that the magnetic anisotropy energy (MAE) of SL H-FeBr$_2$ shows a non-monotonic evolution behaviour with increasing electronic correlation strength, which is mainly due to the competition between different element-resolved MAEs of Fe and Br. Further investigations show that the evolution of element-resolved MAE arises from the variation of the spin-orbital coupling (SOC) interaction between different orbitals in each atom. Moreover, tuning the strength of the electronic correlation can drive the occurrence of band inversions, causing the system to undergoes multiple topological phase transitions, resulting in a quantum anomalous valley Hall (QAVH) effect. These exotic properties are universal for the SL H-FeX$_2$ (X = Cl, Br, I) family. Our work sheds light on the role of electronic correlation effects in tuning magnetic and electronic structures in the SL H-FeX$_2$ (X = Cl, Br, I) family, which could guide advances in the development of new spintronics and valleytronics devices based on these materials.