First-principles Dzyaloshinskii-Moriya interaction in a non-collinear framework.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• The Dzyaloshinskii-Moriya interaction (DMI) is crucial for understanding magnetic phenomena.
• Calculating DMI in non-collinear magnetic configurations is challenging.
• Previous methods often assumed collinearity or spin-orbit coupling.

Purpose of the Study:

• To derive a general expression for DMI applicable to non-collinear magnetic states.
• To implement this formalism within a real-space-linear muffin-tin orbital-atomic sphere approximation (RS-LMTO-ASA) method.
• To investigate the influence of non-collinear magnetism on DMI.

Main Methods:

• Derivation of a general DMI vector expression with independent components.
• Implementation using the RS-LMTO-ASA computational technique.
• Numerical studies on Cr and Mn trimers on noble metal surfaces (Au(111), Ag(111)).

Main Results:

• The DMI magnitude and direction differ significantly between collinear and non-collinear magnetic states.
• DMI can be substantial even without spin-orbit coupling.
• Non-collinear magnetic structures induce significant spin and charge currents.

Conclusions:

• The developed formalism provides a robust way to calculate DMI in complex magnetic systems.
• Non-collinear magnetism is a key factor influencing DMI, independent of spin-orbit coupling.
• This finding opens new avenues for designing materials with tailored magnetic properties.