Magnetic topological Weyl fermions in half-metallic In₂CoSe₄.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Magnetic Weyl semimetals (WSMs) are of great interest for their potential to exhibit strong anomalous Hall effects.
• Designing and identifying new magnetic WSM materials remains a significant challenge in condensed matter physics.

Purpose of the Study:

• To investigate the potential of the ferromagnetic half-metallic compound In2CoSe4 as a magnetic WSM.
• To explore the tunability of its electronic properties and the existence of surface states.

Main Methods:

• First-principles calculations were employed to study the electronic structure of In2CoSe4.
• The effects of Hubbard U and external pressure on the Weyl points were investigated.
• Surface states and Fermi arcs were analyzed through theoretical modeling.

Main Results:

• In2CoSe4 was identified as a magnetic WSM candidate with multiple pairs of Weyl points near the Fermi level.
• The Weyl points' proximity to the Fermi level is tunable with the Hubbard U parameter and external pressure.
• Nontrivial Fermi arcs were discovered in the surface states of In2CoSe4, connecting Weyl points of opposite chirality.

Conclusions:

• In2CoSe4 is a promising material for realizing magnetic WSM states and potentially large anomalous Hall conductivity.
• The tunability of its electronic properties by pressure suggests practical applications.
• The predicted nontrivial surface states are experimentally observable, e.g., via ARPES measurements.