First-principles approach to noncollinear magnetism: towards spin dynamics

Area of Science:

• Condensed Matter Physics
• Quantum Chemistry
• Materials Science

Background:

• Accurate description of noncollinear magnetism is crucial for understanding complex magnetic materials.
• Existing methods often struggle with highly noncollinear magnetic structures.

Purpose of the Study:

• To develop a robust theoretical framework for noncollinear magnetism within spin-density functional theory.
• To investigate the efficacy of the optimized effective potential (OEP) method for magnetic systems.

Main Methods:

• Utilizing the exact exchange energy functional dependent on two-component spinor orbitals.
• Deriving effective Kohn-Sham potentials and magnetic fields via the OEP framework.
• Applying the method to a chromium (Cr) monolayer and bulk Fe, Co, and Ni.

Main Results:

• The developed method reveals significantly more noncollinear magnetization density in Cr monolayers compared to standard calculations.
• The time-dependent generalization enables ab initio description of spin dynamics.
• Accurate reproduction of magnetic moments for Fe, Co, and Ni solids.

Conclusions:

• The noncollinear optimized effective potential method provides a powerful tool for studying complex magnetism.
• This framework is well-suited for ab initio simulations of spin dynamics and magnetic properties.