Layer-Dependent Antiferromagnetic Chern and Axion Insulating States in UOTe

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Magnetic topological insulators offer dissipationless edge states for energy-efficient electronics.
• Existing materials often use ferromagnets with low ordering temperatures and stray fields.
• A challenge is finding antiferromagnetic topological insulators with high Néel temperatures for the quantum anomalous Hall effect (QAHE).

Purpose of the Study:

• To investigate the potential of the van der Waals antiferromagnet UOTe as a material for realizing high-temperature magnetic topological insulator states.
• To explore the layer-dependent topological phases and tunable properties of UOTe.
• To identify UOTe as a platform for next-generation spintronics and fundamental science.

Main Methods:

• Ab initio computations were used to analyze the electronic structure and topological properties of UOTe.
• Systematic analysis of layer-dependent topological phases was performed.
• The effects of in-plane strain and electric fields on UOTe's electronic properties were investigated.

Main Results:

• Two-layer UOTe films are predicted to be 2D antiferromagnetic Chern insulators with quantized Hall conductivity.
• U-5f electron itinerancy can be tuned by strain or electric fields to switch between topological and trivial phases.
• Three-layer UOTe films exhibit quantized spin Hall conductivity and magneto-electric coupling, indicative of an axion insulator-like state.
• UOTe displays layer-tunable topology: even layers are Chern insulators, odd layers are axion-like insulators, and bulk is a Dirac semimetal.

Conclusions:

• UOTe is a promising intrinsic antiferromagnetic material for realizing correlated topological phases.
• Its tunable topological properties make it suitable for advanced spintronics applications.
• The study provides a new material platform for exploring fundamental physics in condensed matter.