Axial Hall Effect in Altermagnetic Lieb Lattices

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Altermagnets exhibit unique electronic and magnetic properties.
• Berry curvature plays a crucial role in anomalous Hall effects.
• Topological degrees of freedom offer novel functionalities.

Purpose of the Study:

• To predict and investigate the axial Hall effect in Lieb-lattice altermagnets.
• To identify the underlying topological mechanism, the axial pseudospin.
• To explore the potential of this effect in material design and spintronics.

Main Methods:

• Tight-binding model calculations.
• First-principles density functional theory (DFT) computations.
• Analysis of spin-orbit coupling and piezomagnetic effects.

Main Results:

• Prediction of a Berry-curvature-driven axial Hall effect.
• Identification of axial pseudospin as a hidden topological degree of freedom.
• Confirmation in strained ternary transition-metal dichalcogenides (e.g., Mn2WS4).
• Demonstration of the effect's origin from spin-orbit coupling and piezomagnetism.
• Observation of a strain-independent, topologically robust effect.
• Thickness-dependent modulation in multilayer structures.

Conclusions:

• The axial Hall effect is a significant phenomenon in Lieb-lattice altermagnets.
• Axial pseudospin is a key topological feature enabling this effect.
• This discovery highlights the importance of spin-orbit coupling and noncollinear spin textures in altermagnets.
• Opens new avenues for exploring intrinsic Hall phenomena and spintronic applications.