Odd-Parity Magnetism Driven by Antiferromagnetic Exchange

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Achieving odd-parity, time-reversal-preserving, nonrelativistic spin splitting is crucial for advancing spintronics.
• Conventional methods often rely on spin-orbit coupling (SOC), limiting material choices and applications.

Purpose of the Study:

• To propose a group-theory-based microscopic framework for inducing odd-parity spin splitting in antiferromagnetic (AFM) states without SOC.
• To explore competing ground states and their associated orders in these AFM systems.

Main Methods:

• Developed phenomenological models for 421 period-doubling AFM systems in nonsymmorphic space groups.
• Constructed minimal microscopic models for 119 of these systems.
• Utilized density-functional theory (DFT) calculations and analyzed material databases (Magndata).

Main Results:

• Identified three competing ground states: odd-parity spin-splitting, nematic order, and scalar odd-parity order.
• Demonstrated that the odd-parity spin-splitting energy scale is generically large.
• Showed that scalar odd-parity order yields a nonzero Berry curvature dipole without SOC.
• Identified 67 candidate materials and confirmed h-wave spin splitting in Fe-based materials.

Conclusions:

• The proposed framework offers a viable route to nonrelativistic spin splitting in AFM materials without SOC.
• The identified ground states and their associated orders open new avenues for spintronics and multiferroic applications.
• The findings provide a theoretical basis for exploring novel electronic and magnetic phenomena in a wide range of materials.