Quantum anomalous Hall effect in M₂X₃honeycomb Kagome lattice

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• The quantum anomalous Hall (QAH) effect, characterized by dissipationless chiral edge states without an external magnetic field, is a key area in spintronics.
• Two-dimensional materials in M2X3 honeycomb Kagome lattices, including metal oxides, sulfides, and metal-organic frameworks, are actively investigated for QAH insulating properties.

Purpose of the Study:

• To propose a general theoretical model explaining the mechanism behind Dirac half metals (without spin-orbital coupling) and topological properties (with spin-orbital coupling) in specific lattice structures.
• To identify new material candidates exhibiting the quantum anomalous Hall effect.

Main Methods:

• Development of a general model combining electron counting rules, crystal field effects, and d-orbital hybridization (dxz, dyz).
• Theoretical prediction and analysis of topological properties in triphenyl-metal lattices M2(C6H4)3 (M = V, Nb, Ta).

Main Results:

• The proposed model successfully explains the mechanism for achieving Dirac half metallic and QAH insulating states.
• Triphenyl-metal lattices, specifically M2(C6H4)3 with M=V, Nb, and Ta, are predicted to be QAH insulators.
• Triphenyl-Nb and triphenyl-Ta lattices exhibit high Curie temperatures and significant nontrivial band gaps.

Conclusions:

• The study provides a fundamental understanding of QAH mechanisms in M2X3 honeycomb Kagome lattices.
• Triphenyl-metal lattices represent promising new materials for realizing the quantum anomalous Hall effect and advancing spintronics technology.