Beyond Orbitally Resolved Magnetic Exchange in CrI_{3} and NiI_{2}

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Understanding magnetic exchange interactions is crucial for designing novel magnetic materials.
• Existing theories often lack a systematic approach to quantify all contributing mechanisms.
• 2D magnetic materials offer unique properties for spintronic applications.

Purpose of the Study:

• To develop a systematic method for quantifying all magnetic exchange mechanisms.
• To apply this method to archetypal 2D magnetic materials like CrI_{3} and NiI_{2}.
• To elucidate the microscopic origins of orbital contributions to magnetic exchange.

Main Methods:

• Development of a novel theoretical framework for calculating magnetic exchange.
• Application of the method to first-principles calculations of CrI_{3} and NiI_{2}.
• Analysis of orbital contributions, focusing on d-orbital interactions.

Main Results:

• The d_{x^{2}-y^{2}},d_{x^{2}-y^{2}} orbital contribution is identified as a leading or second-largest factor in magnetic exchange for CrI_{3} and NiI_{2}.
• Detailed microscopic mechanisms for all nonzero orbital contributions were explored.
• The findings were generalized to other magnetic monolayers with d^{8} and d^{3} electronic configurations.

Conclusions:

• The developed method provides a comprehensive understanding of magnetic exchange.
• The significance of specific d-orbital interactions in 2D magnets is highlighted.
• This work offers insights for the rational design of future magnetic materials.